Field reference for fuel system and underground storage tank technicians. 60 entries, taken from the DropTubeBuilder app.
These notes are the web copy of the DropTubeBuilder reference, built for fuel system and underground storage tank technicians. The same library is free inside the app, with no time limit and no account, and it works with no signal.
Reference notes from DropTubeBuilder, the offline field tool for fuel system technicians who cut overfill drop tubes, build tank charts and chase dispenser faults. It works with no cell signal, because the sites do not have any.
Get DropTubeBuilder on the App StoreFlash program memory failed its integrity check. Action: record configuration, prices and totals before attempting recovery, because recovery may clear them; power cycle and see whether it comes up clean; check the supply for instability or repeated interruptions, which is the usual root cause; check whether a software download was interrupted; reload from the site system if the dispenser supports it; verify every price, grade and configuration value afterwards rather than assuming the reload was complete; reload the correct firmware version for this dispenser and let it finish without interruption; if it recurs the board is failing, so escalate rather than repeatedly reloading
Flash template memory failed its integrity check. Action: record configuration, prices and totals before attempting recovery, because recovery may clear them; power cycle and see whether it comes up clean; check the supply for instability or repeated interruptions, which is the usual root cause; check whether a software download was interrupted; reload from the site system if the dispenser supports it; verify every price, grade and configuration value afterwards rather than assuming the reload was complete; reload the display templates and verify the display shows correctly afterwards; if it recurs the board is failing, so escalate rather than repeatedly reloading
RAM has failed its integrity check. Nothing the dispenser reports can be relied on while this is present. Action: power cycle and see whether it comes up clean; record whatever configuration can still be read; check the supply for instability and check for overheating in the electronics enclosure; check the board for corrosion or water ingress; if RAM fails again after a clean restart the board needs replacing, so do not keep clearing it; verify configuration and calibration fully after any recovery
The dispenser recorded a power failure. Action: check whether this coincides with a known site power event, which makes it informational; check the breaker and incoming supply, measuring under load rather than at rest; check terminations inside the dispenser for looseness and corrosion; check the power supply output; verify configuration, prices and calibration survived the event; if these repeat with no external cause, treat the supply or power board as failing
The error log database failed its integrity check. Action: record configuration, prices and totals before attempting recovery, because recovery may clear them; power cycle and see whether it comes up clean; check the supply for instability or repeated interruptions, which is the usual root cause; check whether a software download was interrupted; reload from the site system if the dispenser supports it; verify every price, grade and configuration value afterwards rather than assuming the reload was complete; note that log history may be lost, so record any codes you still need before recovering; if it recurs the board is failing, so escalate rather than repeatedly reloading
The configuration database failed its integrity check. Action: record configuration, prices and totals before attempting recovery, because recovery may clear them; power cycle and see whether it comes up clean; check the supply for instability or repeated interruptions, which is the usual root cause; check whether a software download was interrupted; reload from the site system if the dispenser supports it; verify every price, grade and configuration value afterwards rather than assuming the reload was complete; verify grade mapping, hose assignments and flow settings specifically, since defaults here change how the dispenser sells; if it recurs the board is failing, so escalate rather than repeatedly reloading
The unit price database failed its integrity check. Action: record configuration, prices and totals before attempting recovery, because recovery may clear them; power cycle and see whether it comes up clean; check the supply for instability or repeated interruptions, which is the usual root cause; check whether a software download was interrupted; reload from the site system if the dispenser supports it; verify every price, grade and configuration value afterwards rather than assuming the reload was complete; verify every price on every grade and both sides before allowing sales, because a wrong price is a billing problem the moment a customer pulls in; if it recurs the board is failing, so escalate rather than repeatedly reloading
The statistics database failed its integrity check. Action: record configuration, prices and totals before attempting recovery, because recovery may clear them; power cycle and see whether it comes up clean; check the supply for instability or repeated interruptions, which is the usual root cause; check whether a software download was interrupted; reload from the site system if the dispenser supports it; verify every price, grade and configuration value afterwards rather than assuming the reload was complete; if it recurs the board is failing, so escalate rather than repeatedly reloading
The event log database failed its integrity check. Action: record configuration, prices and totals before attempting recovery, because recovery may clear them; power cycle and see whether it comes up clean; check the supply for instability or repeated interruptions, which is the usual root cause; check whether a software download was interrupted; reload from the site system if the dispenser supports it; verify every price, grade and configuration value afterwards rather than assuming the reload was complete; if it recurs the board is failing, so escalate rather than repeatedly reloading
The totals database failed its integrity check. Action: record configuration, prices and totals before attempting recovery, because recovery may clear them; power cycle and see whether it comes up clean; check the supply for instability or repeated interruptions, which is the usual root cause; check whether a software download was interrupted; reload from the site system if the dispenser supports it; verify every price, grade and configuration value afterwards rather than assuming the reload was complete; reconcile totals against the site system and record the discrepancy, since totals are what the site reconciles inventory against; if it recurs the board is failing, so escalate rather than repeatedly reloading
The point of sale aborted a filling in progress. Action: establish whether the cashier stopped it deliberately, which is the common and benign explanation; check the POS communication link if aborts happen without operator action; check the two wire or network cabling and terminations for water and corrosion; check whether other positions are also aborting, which points at the site system rather than this dispenser; check the POS software and any recent change to it; read the surrounding entries in the error log, S21.XX for side 1 and S22.XX for side 2, since each entry carries the time, the device number and the logical nozzle and that usually localises the fault faster than the code alone
A hose was activated without authorisation. Product could be delivered without a sale. Action: take the position out of service until this is understood, since it is both a loss and a safety issue; check the hang up switch for sticking or a short, which is the usual cause of a false authorisation; check the switch harness for a chafed conductor shorting to ground; check the valve is not leaking past its seat or held open by a shorted driver; check the POS authorisation path, including whether the position is being authorised by the wrong console key; reconcile against tank inventory to establish whether product actually moved
A meter pulser error has been detected. Action: check the pulser harness and connector at both ends, since the wiring fails far more often than the pulser; check the pulser is correctly mounted and driven, because a slipping or misaligned coupling corrupts the signal; check for water in the connector; check for electrical noise where the pulser wiring runs near power conductors; check the pulser is the correct type and part for this meter, particularly after a replacement; swap in a known good pulser to separate the pulser from the wiring; read the surrounding entries in the error log, S21.XX for side 1 and S22.XX for side 2, since each entry carries the time, the device number and the logical nozzle and that usually localises the fault faster than the code alone
The blend ratio is out of tolerance, so the delivered grade may be off specification. Action: check both product legs are flowing at their expected rates before touching the blend settings; check the dispenser filters on both legs, since a partly blocked filter on one leg is the most common cause; check both shear valves are fully open; check both STPs are running and making normal pressure; check the blend valves for sticking or leakage; check the programmed ratio against the site's product specification; prove each blended grade after correcting, because customers may have received off specification fuel while this was active
Blender calibration failed. Action: confirm both legs flow normally before attempting calibration again, since calibration cannot succeed on a starved leg; check filters, shear valves and STP pressure on both legs; check the meters and pulsers on both legs are reporting correctly; check the test measure and the calibration procedure being used; repeat the calibration and prove each blended grade; Breaking a Weights and Measures seal to reach calibration is restricted to a registered service agent in most states, so confirm you are permitted before opening it, and arrange resealing and any required W&M notification afterwards
The overflow limit was reached, so the delivery exceeded the maximum the dispenser allows. Action: establish whether this was a genuine large fill, such as a commercial vehicle, which makes it expected; check the configured overflow limit is appropriate for the traffic this site actually serves; check the pulser for false pulses inflating the recorded volume; check the meter and its calibration if the recorded volume does not match what was delivered; prove the meter if the volume is genuinely wrong rather than merely large
A hose test volume came out of tolerance. The dispenser tests itself and this one did not pass. Action: treat a single occurrence as information and watch for repeats, since one off results have many benign causes; check the meter and pulser for the affected hose; check the hose and nozzle for leakage, which shows up as a volume discrepancy; check for air in the line, which is the classic cause of a volume test failing; check the filter and flow rate on that hose; prove the meter against a certified test measure if it repeats; read the surrounding entries in the error log, S21.XX for side 1 and S22.XX for side 2, since each entry carries the time, the device number and the logical nozzle and that usually localises the fault faster than the code alone
A hose test volume was out of tolerance on three consecutive fillings. Three in a row is a trend, not a coincidence, and the measurement on that hose should not be trusted. Action: take the hose out of sale until it is proven, because at this point billed volume is in question; check for air in the line, which is the most common repeatable cause; check the meter for wear, debris or damage; check the pulser and its coupling; check the hose, nozzle and swivel for leakage; check the check valve; prove the meter against a certified test measure and recalibrate if required; Breaking a Weights and Measures seal to reach calibration is restricted to a registered service agent in most states, so confirm you are permitted before opening it, and arrange resealing and any required W&M notification afterwards
The flow rate is out of range. Action: check the dispenser filter first, since a blocked filter is by far the most common cause of low flow; check the shear valve is fully open; check the STP is running and making normal pressure, and check for a failing pump or a slipping starting capacitor; check the nozzle and hose for restriction or damage; check the flow control valve is opening fully; check the tank has product and no water at the intake; if flow is too high rather than too low, check the flow control setting and the valve for a stuck open condition
A display read back error, meaning what the dispenser sent to the display is not what the display reports showing. What the customer sees may not match the transaction. Action: take the position out of sale if price or volume is displaying wrongly, since this is a billing issue; check the display harness and connector, because a loose connector is reported as a display failure far more often than a display has actually failed; check for water ingress behind the display; check for electrical noise on the display wiring; reseat the connector and power cycle; verify displayed price and volume against an actual dispense before returning to sale
The keypad is malfunctioning. Action: check for a stuck key, and check the keypad physically for dirt, ice or a swollen gasket holding a key in; check the keypad harness and connector for water and loose pins; disconnect the keypad, and if the fault clears the keypad or its cable is at fault, if it persists the board input is; check the harness for a chafed conductor shorting to ground; check the panel is not over tightened onto the keypad; test every key after any repair rather than only the one that failed
Card reader communication has failed. Action: check the reader cable and its connectors first, because the cable fails considerably more often than the reader; check for water in the connector; check the reader has power; check the cable where it flexes at the door hinge, which is where these normally break; check whether the payment terminal is also reporting faults, which points upstream; swap with a known good reader only once the cable is proven
A printer error, either a paper jam or out of paper. Action: check for paper and reload with the correct roll if empty; clear any jam and check the paper path is clean and the roll is loaded the right way round; check the paper is the correct type, since the wrong stock jams repeatedly; check the cutter and the feed mechanism for debris; check the printer connector and harness if it does not respond at all; keep spare rolls on site
The payment terminal is unresponsive. Action: check the terminal has power; check its communication cable and connectors, including where the cable flexes at the door; check whether other positions are also affected, which separates a site fault from this dispenser; check whether the payment network or the site system was recently changed or updated; power cycle the terminal and then the dispenser; check the terminal's software version if it followed an update
A filling started with a zero unit price. Product can be delivered without being charged for. Action: take the position out of sale immediately, since this is a direct revenue loss; check the price for every grade on that side; check whether a price download from the POS failed or delivered a zero; check the POS price file for the affected grade; re download prices and confirm they arrive at the dispenser; reconcile sales made while the price was zero, since those transactions need addressing with the site owner
A filling started with no unit price downloaded. The dispenser never received a price. Action: take the position out of sale until prices are present; check the POS communication link and the two wire or network cabling; check the price file at the POS includes this position and grade; check the dispenser's address matches what the POS expects, since a wrong address receives someone else's prices or none; re download prices and confirm they arrive; verify every grade before returning to sale
A filling started immediately after a unit price change. The concern is whether the customer was charged the price that was displayed to them. Action: check whether the price change was authorised and expected; verify the displayed price and the charged price now agree; check the POS price change timing, since changes during a transaction cause disputes; check for repeated unexplained price changes, which would point at a POS or communication problem; confirm current prices are correct on both the display and the POS
A filling started without a preset entry where a preset was expected. Action: check the configuration for whether presets are required at this position; check the keypad and its harness, since a failed keypad prevents preset entry; check the POS is sending the preset correctly; check whether the site's operating mode changed, for example prepay to postpay; test a preset transaction after any correction
A nozzle was removed without authorisation. Action: check the hang up switch for sticking, damage or water, which is the usual cause of a false report; check the switch adjustment, since a maladjusted switch reads as lifted; check the switch harness for a short to ground; check whether product actually moved, because a nozzle lifted with no flow is a switch problem and one with flow is a security problem; check the valve is not passing product; reconcile against inventory if flow occurred
Communication with the point of sale has been lost. Action: check whether other dispensers are also disconnected, which separates a site fault from this one immediately; check the two wire or network cable and terminations at the dispenser junction box for water and corrosion; check the site controller and interface board are powered and running; check whether the POS was restarted, updated or reconfigured; check the dispenser's address matches what the POS expects; check for a duplicate address on the loop, which causes intermittent dropouts at both positions
The price changed during a dispensing transaction. This creates a dispute about what the customer agreed to pay. Action: establish what the customer was actually charged against what was displayed when they started; check the POS price change schedule, since changes pushed during trading cause this; check whether the price change was authorised; advise the site to schedule price changes outside trading where possible; check for repeated unexplained changes, which points at a POS or communication fault rather than an operator
The pulser signal was interrupted during a delivery. Volume measurement was broken part way through. Action: check the pulser harness and connector, particularly for an intermittent break where the cable flexes; check for water in the connector; check the pulser mounting and coupling for slipping; check for electrical noise on the signal wiring, especially near power conductors and contactors; check the pulser itself by swapping in a known good unit; prove the meter afterwards, since volume delivered during the interruption is in question; read the surrounding entries in the error log, S21.XX for side 1 and S22.XX for side 2, since each entry carries the time, the device number and the logical nozzle and that usually localises the fault faster than the code alone
The pulser frequency is out of range, so the signal is present but wrong. Action: check the pulser is the correct type and part for this meter, which is the usual cause after a replacement; check the pulser coupling for slipping or misalignment; check the programmed pulses per unit against the pulser actually fitted, because a mismatch makes every measurement wrong; check for noise on the signal wiring; check the meter is turning freely and not partly seized; prove the meter before returning to sale; Breaking a Weights and Measures seal to reach calibration is restricted to a registered service agent in most states, so confirm you are permitted before opening it, and arrange resealing and any required W&M notification afterwards
A product mismatch has been detected. What the dispenser thinks it is delivering does not match what is actually plumbed or configured. Action: take the position out of sale, since the risk is delivering the wrong product to a customer; check the grade mapping in configuration against what is physically plumbed to each meter and hose; check the hose and nozzle assignments; check whether recent work changed the plumbing without the configuration following; check the tank assignments for each product; verify by dispensing and confirming the product actually delivered before returning to sale
Blending is out of tolerance. Action: check both legs are flowing at their expected rates before adjusting anything; check the filters on both legs, since one partly blocked filter throws the ratio; check both shear valves are fully open and both STPs are making pressure; check the blend valves for sticking or leakage between products; check the meters and pulsers on both legs; check the programmed ratio against the product specification; prove each blended grade after correcting
No flow on one meter at high speed on a blender pump, so one leg drops out when demand rises. Action: check the filter on the affected leg, since a partly blocked filter passes at low flow and starves at high flow, which is exactly this symptom; check the shear valve on that leg is fully open rather than partly closed; check the STP for that product is making full pressure under load, not just at rest; check for a restriction in the piping on that leg; check the blend valve opens fully; check the tank level and for water at the intake; test at full flow rather than at idle, because this fault hides at low flow rates
The vapour monitor recorded ten bad fillings. The monitoring system is reporting persistent failure rather than a one off. Action: check the vapour hoses, boots and bellows for damage, kinks and blockage; check the nozzles for blocked vapour paths and damaged bellows; check the vapour pump or motor is running and making its expected flow; check for liquid in the vapour return path, which is a common cause of repeated failures; check the monitoring sensor and its wiring; your local air district sets the requirements, so check what testing and reporting is required after repair
Seventy two hours have elapsed on the vapour monitor without a satisfactory result. This is usually a compliance timer rather than a new fault. Action: check whether an underlying vapour fault has been sitting unresolved, and work that first; check the vapour hoses, boots, nozzles and vacuum source; check the monitoring sensor and wiring; check what your local air district requires once this timer expires, since some jurisdictions require the position to be taken out of service; record the elapsed period, because vapour recovery has its own compliance record
The vapour monitor has reported an internal error. The monitoring itself has failed, so the vapour system is unmonitored even if it is working. Action: check the monitor has power and its wiring is sound; check the sensor and its connector for contamination and water; power cycle and see whether it clears; check the monitor's software version if this followed an update; check what your local air district requires while monitoring is out of service; verify the vapour system itself is working, since the monitor failing does not mean the system is fine
The vapour monitor was reset. Action: establish whether the reset was deliberate, since a technician resetting after a repair is normal; if nobody reset it, check for power interruptions to the monitor; check what fault was present before the reset, because resetting without repairing simply restarts the clock; confirm the vapour system is actually working after the reset rather than assuming it; record the reset for your vapour recovery compliance file
A motor feedback error, so the motor is not reporting back as expected. Action: check the motor has power at its connector, which separates a drive fault from a motor fault; check the feedback wiring and connector; check the motor turns freely rather than being seized or loaded; check for liquid or blockage loading the motor; check the drive board and its output; swap with a known good motor only once the drive and wiring are proven
The vapour system is not calibrated. Action: do not return the position to service on an uncalibrated vapour system, since this is an air district compliance matter; establish whether calibration was lost or never performed, because lost calibration points at a fault that will recur; check whether a recent board or component swap cleared it; calibrate following the manufacturer procedure and the requirements of your local air district; record the calibration in the vapour recovery compliance file
Vapour valve current is low, so the valve is drawing less than expected. That usually means an open or high resistance circuit rather than a valve problem. Action: check the valve connector and harness for corrosion, water and loose pins; check the coil resistance against the manufacturer specification; check for a partly broken conductor, which raises resistance without going fully open; check the drive board output; replace the valve only once the wiring is proven sound
Vapour valve current is high, so the valve is drawing more than expected. That usually means a shorted coil or a short in the harness. Action: disconnect the valve and check whether the fault clears, which separates the valve from the harness; check the coil resistance against specification; check the harness for a chafed conductor shorting to ground or to another conductor; check for water in the connector bridging pins; check the drive board has not been damaged by the overcurrent; replace whichever the test identifies rather than both
A vapour contactor error. Action: check the contactor is pulling in and its contacts are not welded or badly pitted; check the coil and its drive; check the control wiring and terminations; check for a mechanical obstruction preventing the contactor operating; check the load side for a fault that damaged the contacts; replace the contactor if the contacts are damaged, and find what damaged them so it does not repeat
An external error was detected by the vapour system, meaning the fault is reported from outside the dispenser. Action: identify what external device is reporting, since the fault is not in the dispenser itself; check the vapour processor or central vacuum unit if the site has one; check the interconnecting wiring and terminations; check whether other dispensers are reporting the same thing, which confirms a site level fault; check the external device's own indications and documentation; check what your local air district requires while the system is faulted
A vapour electrical error. Action: check power to the vapour components; check wiring, terminations and connectors for water, corrosion and looseness; check for a tripped protective device; check the drive board and its outputs; check for a short or ground fault in the vapour wiring; isolate by disconnecting components one at a time to find which circuit is at fault
The vapour flow rate is too low, so the system is running but not moving enough vapour. Action: check the vapour hoses and boots for kinks, crushing and blockage; check the nozzle vapour paths and bellows, which is where restriction most often develops; check for liquid in the vapour return path; check the vapour pump or motor is running at full speed and not partly stalled; check the vapour piping back toward the tank for restriction or liquid blockage; test the flow after repair against the requirement your local air district enforces
The vapour pump is running without authorisation. Action: check the drive circuit for a shorted output holding the pump on; check the control wiring for a short energising the pump; check the contactor for welded contacts, which is a common cause of a motor that will not stop; check the control board; isolate the pump until the cause is found, since a motor that cannot be commanded off is a safety concern; check for water in the control wiring bridging the circuit
A temperature sensor has failed. Action: check the sensor wiring and connector, which fails more often than the sensor; check the connector for water and corrosion; compare the reading against another position on the same site; check the sensor against a known reference; note that temperature affects compensated volume, so verify compensation operation after repair; prove the meter if compensated volume was affected
The internal clock has drifted beyond its allowed range. Timestamps on transactions and errors are unreliable, which matters when reconciling or investigating. Action: set the correct date and time; check the backup battery, since drift is the classic early symptom of a failing one; replace the battery before it fails completely and takes configuration with it; check whether configuration was also affected; confirm the time holds across a power cycle rather than assuming setting it was enough
Price per unit initialisation timed out, so the price displays did not come up. Action: check the display harnesses and connectors; check the displays have power; check addressing for duplicates or gaps, which is common after a display swap; check the display software versions; power cycle and let initialisation complete; confirm every display shows the correct grade and price before allowing sales
A preset was not acknowledged. Action: check the POS communication link; check the keypad and its harness if the preset is entered at the dispenser; check whether the position is configured for presets at all; check the dispenser address matches what the POS expects; test a preset transaction after any correction
Calibration data is corrupted. The dispenser cannot be relied on for measurement and cannot legally be used for sale in this state until it is recalibrated. Action: take the position out of sale immediately; record what calibration data can still be read; establish the cause, commonly a power event, a failed board or an interrupted software download, because it will recur otherwise; check the supply and the backup battery; recalibrate and prove the meter against a certified test measure; arrange resealing and any required notification; Breaking a Weights and Measures seal to reach calibration is restricted to a registered service agent in most states, so confirm you are permitted before opening it, and arrange resealing and any required W&M notification afterwards
A firmware update failed. The dispenser may be left in an incomplete state. Action: do not leave it part programmed, repeat the update to completion; check the supply is stable before retrying, since an interruption during flash writing causes this; check the communication path to whatever is delivering the update; confirm the version is correct for this dispenser hardware; verify configuration and calibration after a successful update; if the update fails again after a clean retry, the board is suspect
A security seal tamper has been detected. Something monitored was opened. Action: document the event with its timestamp before clearing anything; establish whether authorised service work explains it, which is the common benign cause; if nobody can account for it, inspect the meter, pulser and wiring for interference or an added device; check calibration and sealed settings for changes; escalate to the site owner rather than quietly resetting if tampering is suspected; prove the meter before returning to sale; Breaking a Weights and Measures seal to reach calibration is restricted to a registered service agent in most states, so confirm you are permitted before opening it, and arrange resealing and any required W&M notification afterwards
A meter proving test failed. The meter is not measuring within tolerance. Action: take the position out of sale, since billed volume is outside tolerance; check for air in the line, which is the most common cause of a failed prove and is not a meter fault; check the test measure and the procedure being used before condemning the meter; check the hose, nozzle and swivel for leakage; check the check valve; check the meter for wear, debris or damage; recalibrate and reprove, and arrange resealing; Breaking a Weights and Measures seal to reach calibration is restricted to a registered service agent in most states, so confirm you are permitted before opening it, and arrange resealing and any required W&M notification afterwards
Unauthorised access has been detected. Action: document the event with its timestamp before clearing; establish whether authorised work explains it; check what was accessed and whether any setting changed, particularly prices and calibration; check door switches and locks for damage or tampering; escalate to the site owner if it cannot be accounted for; verify configuration and calibration before returning to sale
The emergency stop was activated. Action: find out why it was pressed before resetting it, because it may have been pressed for a real emergency; check the site for the condition that prompted it, including spills, fire and vehicle impact; confirm the site is safe before restoring power to anything; reset the E stop only once the cause is known and cleared; if the E stop reports activated when it is not, check the switch, its wiring and its connector for a short; test the E stop function after any work on it, since it is a safety device
The leak detection system has failed. The line is unmonitored until this is restored, which is a compliance gap as well as an equipment fault. Action: identify which leak detection device is reporting, mechanical or electronic; check the device wiring, terminations and connector; check the device has power; check for water in the sump affecting the equipment; check the device itself against its manufacturer procedure; restore line leak detection promptly, and record the outage because the site still needs a valid release detection record for the period
Reference notes from DropTubeBuilder, the offline field tool for fuel system technicians who cut overfill drop tubes, build tank charts and chase dispenser faults. It works with no cell signal, because the sites do not have any.
Get DropTubeBuilder on the App StoreThese notes are a field aid, not a substitute for the governing codes, the stamped drawings, the authority having jurisdiction, or manufacturer manuals. Verify against the current documentation for your installed equipment.