Dtc trouble code index (Discovery 3)

NOTE: Generic scan tools may not be able to read the codes listed or may only be able to read 5-digit codes. Match the 5 digits from the scan tool with the first 5 digits of the listed 7-digit code to identify the fault. (the last 2 digits provide additional information readable by an approved diagnostic system).

NOTE: Intermittent malfunctions may cause DTCs to be stored, however, some DTCs may be cleared during an ignition cycle. Perform a road test (if it is safe), check the system functionality and read all DTCs before turning off the ignition.

DTC	Description	Possible reasons	Action
P056200	Low voltage in the system	Rear differential control unit supply voltage below 9 V	Check the charging status, refer to the electrical manual and check the electrical circuit of the differential actuator, repair if necessary.
P056300	High voltage in the system	Rear differential control unit supply voltage below 16 V	Check the charging circuit and power status.
P060400	Internal Control Module Direct Access Memory (RAM) Error	Rear Differential Control Unit Internal Error	Clear DTCs and retest. If problem persists, replace control module. If module is suspected, refer to warranty policy and procedures manual.
P060500	Internal Control Module Read Only Memory (ROM) Error	Rear Differential Control Unit Internal Error	Clear DTCs and retest. If problem persists, replace control module. If module is suspected, refer to warranty policy and procedures manual.
P060600	Control unit processor	Resetting the monitoring device	This is a control module internal check DTC and does not necessarily indicate a malfunction. If no other DTCs are logged and there are no customer complaints, clear/ignore this DTC.
P060700	Problems with the performance of the control unit	Rear Differential Control Unit Internal Error	Clear DTCs and retest. If problem persists, replace control module. If module is suspected, refer to warranty policy and procedures manual.
P065200	Low reference voltage in the sensor circuit "B"	The supply voltage of the internal position sensor of the actuator is below 57V	Refer to the electrical equipment manual and check the electrical circuit of the differential actuator position sensor, and repair it if necessary. If the electrical circuit is working properly, replace the differential actuator.
P065300	High reference voltage in the sensor circuit "B"	The supply voltage of the internal position sensor of the actuator is below 83V	Refer to the electrical equipment manual and check the electrical circuit of the differential actuator position sensor, and repair it if necessary. If the electrical circuit is working properly, replace the differential actuator.
P066600	PCM/ECM/TCM Internal Temperature Sensor "A" Circuit	Rear Differential Control Module Internal Temperature Sensor Value Exceeds 105°C	This is an internal control module check DTC and does not necessarily indicate a malfunction. If no other DTCs are logged and there are no customer complaints, clear this DTC and retest. If the problem persists, replace the control module. If a module is suspected, refer to the warranty policy and procedures manual.
P071200	Low Voltage in Transmission Fluid Temperature Sensor "A" Circuit	Open or short circuit to ground in the electrical circuit of the internal temperature sensor of the differential actuator	Refer to the electrical equipment manual and check the electrical circuit of the differential actuator sensor, and repair it if necessary. If the electrical circuit is working properly, replace the differential actuator.
P071300	Transmission Fluid Temperature Sensor "A" Circuit High Voltage	Open or short circuit on +battery of the electrical circuit of the internal temperature sensor of the differential actuator	Refer to the electrical equipment manual and check the electrical circuit of the differential actuator sensor, and repair it if necessary. If the electrical circuit is working properly, replace the differential actuator.
P080600	Clutch Actuator Position Sensor Circuit Range/Performance Problems	Discrepancy between actual and expected/calculated position of the actuator Internal error of the differential actuator	Calibrate the clutch and range change mechanism using the approved diagnostic system or according to the procedure specified in the Design and Operation Description. Refer to the appropriate section in the workshop manual. Clear the DTCs and retest. If the problem persists, replace the differential actuator.
P080700	Low voltage in the clutch actuator position sensor circuit	Internal differential actuator position sensor: open in power supply, ground, signal circuit 1 or 2, or short to ground in power supply, signal circuit 1 or 2	Refer to the electrical manual and check the differential actuator electrical circuit, repair if necessary. If the electrical circuit is normal, replace the differential actuator.
P080800	High voltage in the clutch actuator position sensor circuit	Short circuit to +battery signal circuit 1 or 2 of the internal differential actuator position sensor	Refer to the electrical manual and check the differential actuator electrical circuit, repair if necessary. If the electrical circuit is normal, replace the differential actuator.
P080A00	Clutch position not programmed	Rear Differential Control Module (RDCM) Not Calibrated Differential clutch sticking or clutch out of tolerance	Using the approved diagnostic system, calibrate the rear differential control module. Clear the DTCs and retest. If the problem persists, replace the rear differential assembly. If the differential is suspected, refer to the warranty policy and procedures manual.
P089400	Slippage of gearbox elements	Slippage of the internal electromagnetic brake of the differential actuator	Replace the differential actuator.
P090000	Break in the electrical circuit of the clutch actuator	Break in the electrical power supply circuit of the differential actuator	Refer to the electrical manual and check the differential actuator electrical circuit, repair if necessary.
P090100	Clutch actuator electrical circuit operating range/performance issues	Short circuit in the electrical power supply circuit of the differential actuator	Refer to the electrical manual and check the differential actuator electrical circuit, repair if necessary.
P090200	Low voltage in the clutch actuator circuit	Short circuit to ground in the electrical power supply circuit of the differential actuator.	Refer to the electrical manual and check the differential actuator electrical circuit, repair if necessary.
P090300	High voltage in the clutch actuator circuit	Short circuit to +battery of the electrical power supply circuit of the differential actuator	Refer to the electrical manual and check the differential actuator electrical circuit, repair if necessary.
P160300	EEPROM failure	Rear Differential Control Unit Internal Error	Clear DTCs and retest. If problem persists, replace control module. If module is suspected, refer to warranty policy and procedures manual.
P178300	Gearbox overheating condition	Rear Differential Oil Pan Temperature Sensor Value Exceeds 150°C	Check the customer complaint and vehicle usage at the time the DTC was recorded. Check the operation of the rear differential. Check the rear differential fluid level and specification. Refer to the appropriate section in the service manual. Clear the DTCs and retest. If the problem persists, replace the rear differential assembly. If the differential is suspected, refer to the warranty policy and procedures manual.
P186A00	Open circuit in the electrical control circuit of the differential lock actuator brake	Break in the electrical circuit of the end terminals of the power supply of the internal electromagnetic brake of the actuator	Refer to the electrical manual and check the differential actuator electrical circuit, repair if necessary. If the electrical circuit is normal, replace the differential actuator.
P186B00	Low voltage in the differential lock actuator brake control circuit	Short circuit to ground of both pins of the internal electromagnetic brake of the differential actuator	Refer to the electrical manual and check the differential actuator electrical circuit, repair if necessary. If the electrical circuit is normal, replace the differential actuator.
P186C00	High voltage in differential lock actuator brake control circuit	Short circuit to +battery of both pins of the internal electromagnetic brake of the differential actuator	Refer to the electrical manual and check the differential actuator electrical circuit, repair if necessary. If the electrical circuit is normal, replace the differential actuator.
P186D00	Clutch actuator jamming	Actuator failure	Using the approved diagnostic system, calibrate the rear differential clutch control module/actuator. Clear the DTCs and retest. If the problem persists, replace the actuator.
P274200	Low voltage in the electrical circuit of the sensor "B" of the temperature of the transmission fluid	Short circuit to ground in the rear differential oil pan temperature sensor circuit	Refer to the electrical manual and check the differential oil temperature sensor circuit, repair if necessary.
P274300	Transmission Fluid Temperature Sensor "B" Circuit High Voltage	Open or short circuit to +battery in the electrical circuit of the rear differential oil pan temperature sensor	Refer to the electrical manual and check the differential oil temperature sensor circuit, repair if necessary.
P278500	Clutch actuator temperature too high	The actuator internal temperature sensor value is greater than 150°C. Continuous off-road use. Insufficient oil volume. Incorrect oil specification. Internal differential malfunction.	Check the customer complaint and vehicle usage at the time the DTC was recorded. Check the operation of the rear differential. Check the rear differential fluid level and specification. Refer to the appropriate section in the service manual. Clear the DTCs and retest. If the problem persists, replace the rear differential assembly. If the differential is suspected, refer to the warranty policy and procedures manual.
P278700	Coupling temperature too high	The temperature (calculated) of the clutch friction disc pack exceeds 200°C	Check the customer complaint and vehicle usage at the time the DTC was recorded. Check the operation of the rear differential. Check the rear differential fluid level and specification. Refer to the appropriate section in the service manual. Clear the DTCs and retest. If the problem persists, replace the rear differential assembly. If the differential is suspected, refer to the warranty policy and procedures manual.
U000188	High-speed CAN data bus	High-speed CAN data bus (cAN bus is disabled)	Refer to the "Network Communication" section in the service station manual.
U010287	Lost communication with the transfer case control unit	Lost connection with TCCM	Refer to the description of the "Bus Off" condition in section 418-00 of the service manual. Refer to the "Network Communications" section of the service manual.
U012287	Lost Communication with Vehicle Dynamics Control Module	Lost connection with VDM	Refer to the description of the "Bus Off" condition in section 418-00 of the service manual. Refer to the "Network Communications" section of the service manual.
U030055	Internal control unit software incompatibility	Rear differential control unit configuration not set	Configure the module using an approved diagnostic system.
U1A1449	CAN initialization failure	Rear Differential Control Unit Monitoring Software Error Internal control module failure	Configure the module using the approved diagnostic system. Clear the DTCs and retest. If the problem persists, replace the control module. If the module is suspected, refer to the warranty policy and procedures manual.