FAULT: WATCHDOG

Microprocessor self-test failure - controller software/hardware malfunction.

Possible Causes:

Controller processor crashed or frozen.

Software corruption.

Power supply instability.

Hardware failure on logic board.

Solutions:

Cycle power (key off/on) to reset controller.

Check battery voltage is stable and within specification.

Verify all power connections secure.

If alarm persists after reset: replace controller immediately.

DO NOT operate truck with persistent watchdog alarm.

FAULT: LOGIC FAILURE #3, #2, #1

Internal logic circuit failures - different numbers indicate different internal faults.

Solutions:

Cycle power to reset.

Check all controller connections are secure.

If persists: replace controller.

Note alarm number for warranty/technical support.

FAULT: VMN LOW

Motor negative voltage below expected range - indicates motor circuit or contactor problem.

Possible Causes:

Contactor stuck closed.

Motor cables incorrectly connected (crossed armature/field).

Poor connections in motor circuit.

Motor insulation breakdown.

Controller internal failure.

Solutions:

Disconnect motor from battery - if alarm clears, check contactors.

Verify motor cable connections are correct.

Check all contactors operate properly (open when should).

Test motor insulation with megger.

Inspect for shorts in contactor board area.

If no external faults: replace controller.

FAULT: VMN HIGH

Motor negative voltage too high in standby - contactor stuck or short circuit.

Solutions:

Check all contactors open in standby.

Look for metallic debris causing shorts.

Verify no contactor is stuck closed.

Replace stuck contactors.

If contactors OK: replace controller.

FAULT: CONTACTOR CLOSED

Contactor stuck in closed position when it should be open.

Solutions:

Identify which contactor is stuck.

Clean contacts with compressed air.

Check for welded contacts.

Replace contactor if damaged.

Verify coil de-energizes when should.

FAULT: CONTACTOR OPEN

Contactor fails to close when commanded.

Solutions:

Check voltage at contactor coil when activated.

If voltage present but no closure: bad coil or mechanical jam.

Test coil resistance with ohmmeter.

Check coil voltage rating matches battery.

Verify wiring to contactor is intact.

Replace faulty contactor.

FAULT: STBY I HIGH

Current detected in standby when should be zero - current sensor or controller fault.

Solutions:

Check current sensor connections.

Verify no contactor stuck causing current flow.

Replace controller if sensor internal.

FAULT: CAPACITOR CHARGE

Internal capacitor charging issue.

Solutions:

Allow 5 minutes with key off for capacitors to discharge.

Verify battery voltage within spec.

If persistent: replace controller.

FAULT: TH. PROTECTION

Controller temperature exceeded safe limits (typically >80°C). Performance reduced.

Solutions:

If cold: Check thermal sensor, replace controller.

If hot: Allow cooling, check mounting/heat dissipation.

Verify controller mounted to clean metal surface.

Check thermal paste applied.

Ensure adequate ventilation.

Consider forced air cooling if frequent.

FAULT: MOTOR TEMPERATURE

Traction motor overheating.

Solutions:

Allow motor to cool.

Check motor ventilation not blocked.

Verify motor not overloaded.

Check motor bearings for excessive friction.

Inspect motor brushes for wear.

Check temperature sensor if alarm when cold.

FAULT: BATTERY LOW

Battery charge below threshold - recharge recommended.

Solutions:

Recharge battery immediately.

Check battery voltage matches controller setting.

Test individual cell voltages.

Verify battery connections clean and tight.

Replace battery if degraded/end of life.

FAULT: DRIVER SHORTED

Contactor driver circuit shorted - usually from overvoltage spike.

Solutions:

Identify and remove cause of voltage spike.

Check contactor coil connections.

Verify no shorts in contactor wiring.

Replace controller after fixing cause.

FAULT: CONTACTOR DRIVER

Contactor driver malfunction - similar to A74.

Solutions:

Same as A74.

Check specific contactor driver circuit indicated.

FAULT: VACC NOT OK

Accelerator signal out of range - potentiometer or wiring fault. Machine disabled.

Possible Causes:

Potentiometer wire broken or disconnected.

Potentiometer not calibrated.

Potentiometer failed.

Poor connections.

Solutions:

Check all three potentiometer wires.

Verify potentiometer power supply present.

Perform potentiometer calibration via console.

Test potentiometer resistance (should be 500Ω-10kΩ).

Replace potentiometer if defective.

FAULT: INCORRECT START

Wrong start sequence - pedal/direction active at key-on.

Solutions:

Release all controls before key-on.

Check microswitches not stuck.

Verify correct start sequence: Key → Seat/Handle → Direction.

FAULT: FORW + BACK

Forward and backward requested simultaneously - safety interlock.

Solutions:

Check forward microswitch operation.

Check backward microswitch operation.

Verify microswitches release properly.

Inspect for shorts between direction signals.

FAULT: ENCODER ERROR

Motor encoder malfunction - speed sensing fault.

Solutions:

Check encoder cable connections.

Verify encoder power supply.

Inspect encoder for damage.

Clean encoder sensor if dirty.

Replace encoder if faulty.

Check for correct encoder configuration in controller.

FAULT: PEDAL WIRE KO

Pedal potentiometer wiring fault.

Solutions:

Inspect all pedal wiring for damage.

Check connections at pedal and controller.

Test potentiometer continuity.

Replace damaged wiring.

WARNING: BMS WARNING 0002 - Voltage Low

Battery Management System warning: Battery voltage approaching low limit.

Solutions:

Recharge battery soon.

Check BMS connections and configuration.

Verify cell voltages are balanced.

WARNING: BMS WARNING 0004 - Temperature High

Battery temperature approaching high limit.

Solutions:

Allow battery to cool.

Check battery ventilation.

Reduce duty cycle.

Verify BMS temperature sensors working.

WARNING: BMS WARNING 0008 - Temperature Low

Battery temperature too low for optimal operation.

Solutions:

Allow battery to warm up before heavy use.

Check if battery stored in cold environment.

Consider battery heating system if operating in cold conditions.

WARNING: BMS WARNING 0010 - Current High

Battery current approaching limit.

Solutions:

Reduce load/acceleration.

Check if truck is overloaded.

Verify BMS current limits configured correctly.

WARNING: BMS WARNING 0020 - Charger Connected

BMS detects charger connected - operation inhibited.

Solutions:

Disconnect charger before attempting to drive.

Verify charger interlock functioning.

Check BMS charger detection circuit if no charger connected.

WARNING: BMS WARNINGS 0040-1000

Various BMS system warnings:

A 134 (0040): Temperature High (secondary).

A 135 (0080): Fan Defect (can ignore).

A 136 (0100): Watchdog (can ignore).

A 137 (0200): SD Card (can ignore).

A 138-140: Hardware Warnings.

Solutions:

Check BMS display for specific details.

Verify BMS firmware up to date.

For hardware warnings: inspect BMS unit and connections.

Can continue operation if marked "ignore".

ERROR: BMS ERROR 0001 - Voltage High

Battery voltage exceeded safe maximum. Operation inhibited.

Solutions:

STOP operation immediately.

Check charger settings - may have overcharged.

Verify BMS voltage limits configured correctly.

Test individual cell voltages

Replace BMS or battery if damaged

ERROR: BMS ERROR 0002 - Voltage Low

Battery voltage critically low. Risk of damage.

Solutions:

Recharge battery immediately.

Check for failing cells.

Test cell balance.

Do not continue operation.

ERROR: BMS ERROR 0004 - Current High

Battery current exceeded safe limit.

Solutions:

Reduce load immediately.

Check for motor or controller short.

Verify truck not overloaded.

Check BMS current sensors.

ERROR: BMS ERROR 0008 - Deep Discharge

Battery deeply discharged - potential permanent damage.

Solutions:

Recharge immediately with appropriate charger.

Check for failing cells.

Battery may need replacement if damaged.

Review charging procedures to prevent recurrence.

ERROR: BMS ERROR 0010 - Short Circuit

Short circuit detected in battery system.

Solutions:

STOP all operation immediately.

Disconnect battery.

Inspect all battery connections for shorts.

Check battery case for damage.

Do not reconnect until short located and repaired.

ERROR: BMS ERROR 0020 - Temperature High

Battery temperature exceeded safe maximum.

Solutions:

STOP operation - allow battery to cool.

Check for thermal runaway.

Inspect battery ventilation.

Do not charge until cooled.

May indicate battery failure.

ERROR: BMS ERROR 0040-0200 - Hardware Failure

BMS hardware component failure.

Solutions:

Check all BMS connections.

Verify BMS power supply.

Check BMS fuses.

Replace BMS unit if confirmed hardware fault.

Contact BMS manufacturer for diagnostic support.

ALARM: BELT INC START

Seatbelt not fastened at start (if equipped with seatbelt interlock).

Solutions:

Fasten seatbelt.

Check seatbelt switch operation.

Verify seatbelt switch wiring.

ALARM: SENS BAT TEMP KO

Battery temperature sensor malfunction.

Solutions:

Check sensor connections.

Test sensor resistance.

Verify sensor wiring not damaged.

Replace sensor if faulty.

ALARM: RPM HIGH

Motor RPM exceeded safe limit - overspeed condition.

Solutions:

Check encoder operation.

Verify speed limit settings in controller.

Check for loss of load/traction causing overspeed.

Inspect encoder mounting and alignment.

ALARM: WRONG KET VOLT.

Key switch voltage incorrect.

Solutions:

Check key switch connections.

Verify battery voltage at key switch.

Test key switch operation.

Check for voltage drops in wiring.

ALARM: COIL SHOR. EB.

Electric brake coil shorted.

Solutions:

Test brake coil resistance.

Check for shorts in brake wiring.

Replace brake coil if shorted.

ALARM: MOTOR TEMP. STOP

Motor temperature critical - operation stopped for protection.

Solutions:

Allow motor to cool completely.

Check motor not overloaded.

Inspect motor ventilation.

Check motor temperature sensor.

May indicate motor bearing failure.

ALARM: STEER SENSOR KO

Steering position sensor malfunction.

Solutions:

Check steering sensor connections.

Verify sensor power supply.

Test sensor output signal.

Check sensor mounting and alignment.

Replace sensor if faulty.

ALARM: OVERLOAD

System overload detected - excessive current demand.

Solutions:

Reduce load on truck.

Check for mechanical binding.

Verify motor not stalled.

Check wheel bearings for excessive friction.

Inspect for brake drag.

ALARM: WRONG ENC SET

Encoder configuration incorrect in controller.

Solutions:

Verify encoder type matches controller setting.

Check encoder PPR (pulses per revolution) setting.

Reconfigure controller for correct encoder type.

Consult encoder and controller documentation.

ALARM: TILLER ERROR

Tiller handle malfunction or position error.

Solutions:

Check tiller microswitch operation.

Verify tiller returns to neutral.

Test tiller position sensor if equipped.

Check tiller wiring connections.

ALARM: SMARTDRIVER KO

SmartDriver module communication or malfunction.

Solutions:

Check SmartDriver connections.

Verify SmartDriver power supply.

Test CAN bus communication.

Replace SmartDriver module if faulty.

ALARM: AUX BATT. SHORT.

Auxiliary battery circuit shorted.

Solutions:

Check auxiliary battery connections.

Inspect wiring for shorts to ground.

Verify auxiliary battery not damaged.

Test auxiliary circuit with multimeter.

ALARM: POS. EB. SHORTED

Electric brake positive circuit shorted.

Solutions:

Check brake wiring for shorts.

Inspect brake coil connections.

Test brake circuit isolation.

Replace damaged wiring.

ALARM: MOT.PHASE.SH.

Motor phase shorted (for AC motors).

Solutions:

Test motor phase resistance.

Check motor cables for damage.

Inspect motor connections.

Replace motor if phase winding shorted.

ALARM: Configuration/Parameter Errors

A 197: WRONG SLAVE VER. - Slave controller firmware mismatch.

A 198: M/S PAR CHK MISM - Master/Slave parameter checksum mismatch.

A 199: PARAM TRANSFER - Parameter transfer failure.

Solutions:

Update slave controller firmware to match master.

Reprogram parameters via console.

Verify CAN bus communication.

Check console connection during programming.

ALARM: VDC System Alarms

A 200: VDC OFF SHORTED - VDC disable circuit shorted.

A 201: TORQUE PROFILE - Torque profile error.

A 202: VDC LINK OVERV. - DC link overvoltage.

Solutions:

Check VDC system wiring.

Verify torque profile settings.

Check for regenerative braking issues causing overvoltage.

Test DC link capacitors.

WARNING: BMS WARNING 0001 - Voltage High

Battery voltage approaching high limit (warning level).

Solutions:

Check charger settings.

Verify not overcharging.

Similar to A 141 but warning level only.

ALARM: EPS IN ALARM