ACU FAULT CODES / ACU ERROR CODES

Armrest Controller Unit – The main function of the ACU electronic control unit is to receive commands from the operator and execute the ordered functions by communicating via CAN bus with the corresponding electronic control units. The ACU is a separate electronic control unit located in the right armrest assembly. It differs from other tractor control units in that it does not have a separate mounting box.

John Deere ACU fault codes / John Deere ACU diagnostic trouble codes

ACU 000158.04 (ACU 158.04 )— ACU Switched Supply Voltage Low
Code caused by: PTO switch supply voltage is less than 9.0V for more than one second.

ACU 000177.17 (ACU 177.17)— Engine Speed Limited Due to Cold Oil
Code Caused By: Engine commanded speed above 1500 rpm and transmission oil temperature below 5°C (23°F).

ACU 000237.02 (ACU 237.02)— VIN Security Data Conflict
Code caused by: the vehicle identification number (VIN) obtained from the other control units does not match.

ACU 000237.14 (ACU 237.14)— VIN Security Not Enabled
Code Caused By: The Vehicle Identification Number (VIN) security feature has not been enabled.

ACU 000237.31 (ACU 237.31)— VIN Security Messages Missing
Code caused by: the vehicle identification number (VIN) has not been received from the other control units.

ACU 000581.07 (ACU 581.07)— Transmission Not Responding to Command
Code caused by: The PTI unit does not respond to commands from the armrest control unit.

ACU 000628.02 (ACU 628.02)— ACU EOL Data Fault
Code caused by: end-of-line memory fault during boot.
NOTE: It is sometimes possible to correct EOL data faults by downloading new software. Try to download the software for this application.

ACU 000628.12 (ACU 628.12)— ACU Programming
Code Caused By: The ACU control unit detects that it is performing a software update process.
Control unit response: No functions available until programming is complete.

ACU 000629.11 (ACU 629.11)— ACU Control Unit Fault
Code caused by: RAM test failed during boot.

ACU 000629.12 (ACU 629.12)— ACU Control Unit Fault
Code caused by: The armrest control unit software did not run within the specified time.

ACU 000630.02 (ACU 630.02)— ACU Calibration Fault/Data Invalid
Code caused by: invalid armrest control unit calibration values or calibration memory failure.

ACU 000630.13 (ACU 630.13)— ACU Calibration Fault/Not Calibrated
Code caused by: The armrest control unit has never been calibrated or a bad calibration was saved.

ACU 000974.02 (ACU 974.02)— Hand Throttle Sensor Circuit Voltage Conflict
Code caused by: hand throttle sensor circuits 1 and 2 voltage conflict.

ACU 000974.03 (ACU 974.03)— Hand Throttle Sensor Circuit Voltage High
Code caused by: hand throttle sensor circuit voltage high.

ACU 000974.04 (ACU 974.04)— Hand Throttle Sensor Circuit Voltage Low
Code caused by: hand throttle sensor circuit voltage low.

ACU 001079.03 (ACU 1079.03)— ACU Sensor Supply 1 Voltage High
Code caused by: armrest control sensor supply voltage high.

ACU 001079.04 (ACU 1079.04)— ACU Sensor Supply 1 Voltage Low
Code caused by: armrest control sensor supply voltage low.

ACU 001080.03 (ACU 1080.03)— ACU Sensor Supply 2 Voltage High
Code caused by: armrest control sensor supply voltage high.

ACU 001080.04 (ACU 1080.04)— ACU Sensor Supply 2 Voltage Low

ACU 002000.09 (ACU 2000.09)— ECU Message Missing
Code caused by: The armrest control unit does not receive the required messages from the ECU.

ACU 002003.09 (ACU 2003.09)— PTI or PTP Message Missing
Code caused by: The armrest control unit does not receive the required messages from the PTI or PTP.

ACU 002020.09 (ACU 2020.09)— SFA Message Missing
Code caused by: The armrest control unit does not receive the required messages from the SFA.

ACU 002049.09 (ACU 2049.09)— CAB Message Missing
Code caused by: Armrest control unit not receiving required messages from CAB.

ACU 523664.02 — Speed Band 1 and 2 Switches Conflict
Code caused by: Speed band 1 and 2 switches indicate the same value.
NOTE: The code is only valid for vehicles equipped with the AutoPowr/IVT left inverter option.

ACU 523923.02 — SCV I Control Lever Switch/Sensor Conflict
Code caused by: SCV control lever sensor and switch voltage conflict I.

ACU 523923.03 — SCV I Control Lever Sensor Circuit Voltage High
Code caused by: SCV I control lever sensor voltage high.

ACU 523923.04 — SCV I Control Lever Sensor Circuit Voltage Low
Code caused by: SCV I control lever sensor voltage less than 0.2V.

ACU 523953.02 — AutoPowr/IVT Speed Control Lever Sensor Circuit Conflict
Code caused by: Voltage conflict of sensor 1 and 2 of the speed control lever.

ACU 523953.03 — AutoPowr/IVT Speed Control Lever Sensor Voltage High
Code Caused By: Speed Control Lever Sensor Voltage High.

ACU 523953.04 — AutoPowr/IVT Speed Control Lever Sensor Voltage Low
Code Caused By: AutoPowr/IVT Speed Control Lever Sensor Circuit Low Voltage.

ACU 523954.07 — Speed Band 1 Adjustment Fault
Code caused by: invalid speed band 1 calibration.

ACU 523954.11 — Set Speed Adjuster Conflict
Code caused by: voltage conflict in the fixed speed adjustment control circuit.

ACU 523955.31 – Engine Overload In Manual Mode

ACU 523958.31 — Reversing Ratio Setting Fault
Code Caused By: Incorrect relationship between forward and reverse set speeds.

ACU 523960.17 — Operator Not Present At Low Speeds
Code Caused By: Operator presence not detected at low speeds.

ACU 523960.31 — Operator Not Seated During Reverser Command
Code caused by: absent operator with engaged direction of travel.

ACU 523961.02 — Park Engaged While In Gear
Code caused by: parking function activated with a gear engaged.
NOTE: This code should appear only if the PTI failed.

ACU 523961.07 — Park Lock Engagement Fault
Code Caused By: Parking state does not match desired parking.

ACU 523962.31 — MFWD Speed Incorrect (AutoPowr/IVT only)
Code Caused By: Invalid TDM Speed.

ACU 523963.02 — Speed Band 1 Switch/Voltage Conflict
Code caused by: speed band 1 switch does not correspond to analog voltage.

ACU 523966.31 — Transmission Come Home Mode
Code Caused By: Transmission limp mode activated.

ACU 523967.02 — Speed Band 2 Switch/Voltage Conflict
Code caused by: speed band 2 switch does not correspond to analog voltage.

ACU 523968.02 — iTEC™ 1/2 Switch Circuit Conflict
Code Caused By: iTEC™ 1/2 Switch Circuit Mismatch

ACU 523968.03 — iTEC™ 1/2 Switch Circuits Voltage High
Code caused by: The input of all three iTEC™ 1/2 switches is high.

ACU 523968.04 — iTEC™ 1/2 Switch Circuits Voltage Low
Code caused by: The input of all three iTEC™ 1/2 switches is low.

ACU 524017.31 — Neutral Switch or Forward Slot Voltage Out Of Range
Code caused by: The switch does not clearly indicate whether it is closed or open.

ACU 524018.31 — RHR Neutral/Park Transition Fault
Code caused by: lever too long in transition position.

ACU 524019.31 — RHR Neutral/Not-Neutral Transition Fault
Code Caused By: Lever position in transition for more than five seconds.

ACU 524020.31 — Transmission In Gear at Power Up
Code caused by: right inverter was not in pos. PARK during ignition.

ACU 524021.31 — Multiple Reverser Switches Conflict
Code caused by: failure of one or more reverser lever switches.

ACU 524101.02 — Front Hitch Control Lever Switch/Sensor Circuit Conflict
Code Caused By: Rear Hitch Control Lever Switch Conflicting With Sensor Voltage.

ACU 524101.03 — Front Hitch Control Lever Sensor Circuit Voltage High
Code Caused By: Front Hitch Control Lever Sensor Circuit Voltage High.

ACU 524101.04 — Front Hitch Control Lever Sensor Circuit Voltage Low
Code Caused By: Front Hitch Control Lever Sensor Circuit Voltage Low.

ACU 524102.02 — SCV V Control Lever Switch/Sensor Circuit Conflict
Code caused by: SCV control toggle switch V conflicting with sensor voltage.

ACU 524102.03 — SCV V Control Lever Sensor Circuit Voltage High
Code caused by: SCV control lever sensor circuit high voltage V.

ACU 524102.04 — SCV V Control Lever Sensor Circuit Voltage Low
Code caused by: SCV control lever sensor circuit low voltage V.

ACU 524103.02 — SCV IV Control Lever Switch/Sensor Circuit Conflict
Code Caused By: SCV IV control toggle switch conflicting with sensor voltage.

ACU 524103.03 — SCV IV Control Lever Sensor Circuit Voltage High
Code Caused By: SCV IV Control Lever Sensor Circuit Voltage High.

ACU 524103.04 — SCV IV Control Lever Sensor Circuit Voltage Low
Code Caused By: SCV IV Control Lever Sensor Circuit Voltage Low.

ACU 524104.02 — SCV III Control Lever Switch/Sensor Circuit Conflict
Code Caused By: SCV III Control Toggle Switch Conflicting With Sensor Voltage.

ACU 524104.03 — SCV III Control Lever Sensor Circuit Voltage High
Code Caused By: SCV III Control Lever Sensor Circuit Voltage High.

ACU 524104.04 — SCV III Control Lever Sensor Circuit Voltage Low
Code Caused By: SCV III Control Lever Sensor Circuit Voltage Low.

ACU 524105.02 — SCV II Control Lever Switch/Sensor Circuit Conflict
Code Caused By: SCV II control lever switch conflicting with sensor voltage.

ACU 524105.03 — SCV II Control Lever Sensor Circuit Voltage High
Code Caused By: SCV II Control Lever Sensor Circuit Voltage High.

ACU 524105.04 — SCV II Control Lever Sensor Circuit Voltage Low
Code Caused By: SCV II Control Lever Sensor Circuit Voltage Low.

ACU 524212.02 — Rear Hitch Control Lever Switch/Sensor Circuit Conflict
Code Caused By: Rear Hitch Control Lever Switch Conflicting With Sensor Voltage.

ACU 524212.03 — Rear Hitch Control Lever Sensor Circuit Voltage High
Code Caused By: Rear Hitch Control Lever Sensor Circuit Voltage High.

ACU 524212.04 — Rear Hitch Control Lever Sensor Circuit Voltage Low
Code Caused By: Rear Hitch Control Lever Sensor Circuit Low Voltage.

ACU 524222.02 — Resume Switch Circuit Conflict
Code Caused By: The resume switch shows the same values whether connected or disconnected.

ACU 524224.02 — Rear PTO Switch Circuit Conflict
Code Caused By: The rear PTO switch shows the same values both when
connected as disconnected.

ACU 524254.31 — Transmission Enable Circuit Fault
Code Caused By: Transmission Activation Circuit Incorrect Voltage.