Terrain Response Control Module (ATCM) Trouble Code (Freelander 2)

Inspection and verification

WARNING: Diagnostics using the substitution method from a donor vehicle is PROHIBITED. Substitution of control units does not guarantee confirmation of the fault and, in addition, may cause additional faults in the vehicle being tested and/or in the vehicle from which the units are removed.

1. Perform a visual inspection for obvious mechanical or electrical damage.

Mechanical part	Electrical part
Condition of tires, tire pressure, etc. Transmission, engine, gearbox, suspension, components (correct installation, damage, etc.).	Fuses. Wiring harnesses and electrical connectors. Terrain Response system unit. Engine control unit (ECM). Transmission Control Module (TCM). Anti-lock braking system control unit. Active control unit. Dynamic suspension control unit. CAN network chains.

2. If a clear cause for the problem observed or described by the customer is identified, correct it (if possible) before moving on to further actions.

3. If the cause is not visually obvious, check for DTCs and refer to the DTC Index.

DTC Index

NOTE: If a control module/transmission failure is suspected and the vehicle remains under manufacturer's warranty, refer to the warranty manual (section B1.2) or determine if there is any prior repair approval program in effect before installing a new control module/transmission.

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

NOTE: When performing voltage or resistance tests, always use a digital multimeter (DMM) with three decimal places of accuracy and a valid calibration certificate. When testing resistance, be sure to include the resistance of the DMM leads.

The original text can be found at (lrman.ru)

NOTE: Before starting diagnostic programs using fault location tests, check and correct basic faults.

NOTE: Inspect the connectors for signs of water ingress and their pins for damage and/or corrosion.

NOTE: If DTCs are set and the fault is not present after performing the troubleshooting tests, an intermittent problem may be the cause. Be sure to check for loose connections and corroded terminals.

Description and operation

For a detailed description of the Terrain Response system, please refer to the relevant section "Description and Operation" in the workshop manual. For additional information, please refer to the chapter: Optimising the vehicle's suspension and handling characteristics (204-06 Optimising the vehicle's suspension and handling characteristics, Description and Operation).

DTC	Description	Possible reason	Action
C1A00-46	Control unit calibration/parameter memory failure	The Terrain Response Control Module indicates a failure in the calibration/parameter memory of embedded systems using flash memory. This functions similarly to the EEPROM in systems with embedded RAM/ROM/EEPROM. The non-volatile memory (EEPROM) in the Terrain Response system control unit is damaged.	Correct the cause of this DTS code before troubleshooting other faults. Record all stored DTCs and clear them. With the ignition on, select a Terrain Response special program, turn the ignition off and back on, and verify that the selected special program still operates. If the selected Terrain Response special program is inactive and reverts to a generic program, verify that a diagnostic trouble code (DTC) is stored. Repeat the procedure again. If the DTC is still present, install a new Terrain Response rotary switch and control module. If this module is suspected, refer to the Warranty Policy and Procedures Manual.
C1A01-96	LED indicator circuit: internal component failure	Terrain Response Rotary Switch and Control Unit: Indicator Short to Ground. Terrain Response rotary switch and control unit: indicator circuit open.	NOTE: If the system has entered Safe Mode by default due to another fault, the indicator will not turn on. The fault does not cause the system to enter Safe Mode by default. Refer to the Description and Operation section of the Workshop Manual. Check the Terrain Response system, special program indicators. One or more indicators may not be working properly. With the engine running, rotate the Terrain Response switch through all five programs one by one and check that the corresponding special program indicators do not come on. Possible faulty rotary switch and Terrain Response control unit, check and install a new switch and Terrain Response control unit if necessary, see the note on installing a new module/component at the beginning of the DTC index.
C1A02-94	Rotary switch stuck in middle position: operation not as expected	The rotary switch for adapting to road conditions was held in an intermediate position (between the positions of special programs) for more than 60 seconds. A foreign object is preventing the correct operation of the road conditions adaptation mode rotary switch. Mechanical damage to the rotary switch for adapting to road conditions.	NOTE: Driver may be faulty, do not replace Terrain Response rotary mode switch. Check to see if a foreign object is preventing the Terrain Response rotary switch from operating properly. Start the engine, turn the Terrain Response rotary switch until it locks, and wait 60 seconds. Stop the engine, clear the DTCs, and recheck
U0073-88	Control unit data bus "A" shutdown: bus shutdown	Bus Off The Terrain Response control unit has detected that the data bus is not available. Open circuit in CAN bus. Short circuit to ground in the CAN bus. Short circuit to power supply in CAN bus. Malfunction of another control unit on the CAN bus.	Refer to electrical circuit diagrams and check CAN circuit for open circuit, short circuit to ground, short circuit to power, repair/replace as necessary. Perform network integrity check using the manufacturer approved diagnostic system. Verify that the system functions normally and that the DTC is no longer set.
U0100-87	Lost Communication with ECM/PCM "A": No Message	The road conditions adaptation control unit does not receive one or more expected messages from the engine control unit. Communication failure in the high speed CAN bus circuit. Open circuit in engine control unit, power supply. Open circuit in engine control unit, ground line. The engine control unit is disconnected from the high-speed CAN communication bus. Open circuit in the engine control unit, low voltage in the high-speed CAN bus circuit. Open circuit in the engine control unit, high voltage in the high-speed CAN bus circuit. The engine control unit is not configured. Engine control unit malfunction.	Check for engine control module DTCs using the manufacturer approved diagnostic system and refer to the DTC Index for their meaning. Perform a network integrity check using the manufacturer approved diagnostic system. Reset the engine control module using the manufacturer approved diagnostic system. Refer to the electrical circuit diagrams to check the power and ground lines of the engine control module for an open circuit. Check for an open circuit in the engine control module, low voltage in the high speed CAN circuit. Check for an open circuit in the engine control module, high voltage in the high speed CAN circuit and repair as necessary.
U0101-87	Lost Communication with Transmission Control Module (TCM): No Message	The Terrain Response control module has not received one or more expected messages from the transmission control module. Communication failure in the high speed CAN bus circuit. Open circuit in the gearbox control unit, power supply. Open circuit in the gearbox control unit, ground line. The transmission control unit is disconnected from the high-speed CAN communication bus. Open circuit in the transmission control unit, low voltage in the high-speed CAN bus circuit. Open circuit in the transmission control unit, high voltage in the high-speed CAN bus circuit. The transmission control unit is not configured. Gearbox control unit malfunction.	Check for transmission control module DTCs using the manufacturer approved diagnostic system and refer to the DTC Index for their meaning. Perform a network integrity check using the manufacturer approved diagnostic system. Reset the transmission control module using the manufacturer approved diagnostic system. Refer to the electrical circuit diagrams and check the transmission control module power and ground lines for open circuits. Check for transmission control module open circuit, high speed CAN bus low voltage. Check for transmission control module open circuit, high speed CAN bus high voltage and repair as necessary.
U0121-87	Lost Communication with Anti-lock Brake System (ABS) Control Unit: No Message	The Terrain Response control module has not received one or more expected messages from the anti-lock brake system control module. Communication failure in the high speed CAN bus circuit. Open circuit in the anti-lock brake system control unit: power supply line. Open circuit in the anti-lock brake system control unit: ground line. The anti-lock brake system control unit is disconnected from the high-speed CAN communication bus. Open circuit in the anti-lock brake system control unit: low voltage circuit of the high-speed CAN bus. Open circuit in the anti-lock brake system control unit: high voltage circuit of the high-speed CAN bus. The anti-lock brake system control unit is not configured. Malfunction of the anti-lock braking system control unit.	Using the manufacturer's approved diagnostic system, check the anti-lock brake system control module for DTCs and refer to the applicable DTC index. Perform a network continuity test using the manufacturer approved diagnostic system. Reset the anti-lock brake system control module using the manufacturer approved diagnostic system. Refer to the electrical circuit diagrams and check the power and ground circuits of the anti-lock brake system control module for an open. Check the low voltage circuit of the anti-lock brake system control module high speed CAN for an open. Check the high voltage circuit of the anti-lock brake system control module high speed CAN for an open and repair as necessary. The anti-lock brake system control module is likely to be faulty. Check and install a new anti-lock brake system control module if necessary - see the new module/component installation note at the beginning of the DTC index. Verify that the system is functioning normally and that the DTC is no longer set.
U0136-87	Lost Communication with Rear Differential Control Module: No Message	The Terrain Response control module did not receive one or more expected messages from the rear differential control module. Communication failure in the high speed CAN bus circuit. Open circuit in rear differential control unit: power line. Open circuit in rear differential control unit: ground line. The rear differential control unit is disconnected from the high-speed CAN communication bus. Open circuit in low voltage circuit of high speed CAN bus in rear differential control unit. Open circuit in high voltage circuit of high speed CAN bus in rear differential control unit. The rear differential control unit is not configured. Rear differential control unit malfunction.	Check for rear differential control module DTCs using the manufacturer approved diagnostic system and refer to the DTC Index for their meaning. Perform a network continuity test using the manufacturer approved diagnostic system. Reset the rear differential control module using the manufacturer approved diagnostic system. Refer to the electrical circuit diagrams to check the power and ground lines to the rear differential control module for an open circuit. Check the rear differential control module high speed CAN bus low voltage circuit for an open circuit. Check the rear differential control module high speed CAN bus high voltage circuit for an open circuit and repair as necessary. Possible rear differential control module malfunction. Check and install a new rear differential control module if necessary - see the new module/component installation note at the beginning of the DTC Index. Verify that the system is functioning normally and that the DTC is no longer logged.
U0140-87	No communication with the body control unit: no message	The Terrain Response Control Module has not received one or more expected messages from the Body Control Module. Communication failure in the high speed CAN bus circuit. Open circuit in the body control unit: power line. Open circuit in the body control unit circuit: ground line. The body control unit is disconnected from the high-speed CAN communication bus. Open circuit low voltage in the high-speed CAN bus circuit of the body control unit. Open circuit in high voltage circuit of high speed CAN bus in body control unit. The body control unit is not configured. Malfunction of the body control unit.	Check for body control module DTCs using the manufacturer approved diagnostic system and refer to the DTC Index for their meaning. Perform a network integrity check using the manufacturer approved diagnostic system. Reset the body control module using the manufacturer approved diagnostic system. Refer to the electrical circuit diagrams to check the power and ground lines of the body control module for an open circuit. Check for an open circuit in the body control module high speed CAN low circuit. Check for an open circuit in the body control module high speed CAN high circuit and repair as necessary. Body control module malfunction is suspected. Check and install a new body control module if necessary - refer to the new module/component installation note at the top of the DTC Index. Verify that the system functions normally and that the DTC is no longer stored.
U0300-55	Incompatibility of internal software of control units: not configured	The Terrain Response control unit did not recognize one of the main configuration identifiers on the main CAN bus. Incorrect configuration of the CAN control unit of the Terrain Response system. The CAN bus controller is not configured correctly. The message containing the configuration code was not received due to a problem with the CAN bus. The message containing the configuration code was not transmitted by the CAN bus controller.	Using the manufacturer's approved diagnostic system, check the CAN bus configuration in the Terrain Response control unit and software versions - update if necessary. If similar DTCs are present from other units, there may be a fault with the CAN bus or the CAN bus controller electronic control unit - check the CAN bus operation, e configuration in the bus controller unit, as well as the software versions, update if necessary. Verify that the system is functioning normally and that the DTC is no longer registered.
U0401-94	Invalid data received from engine control unit/powertrain control unit (ECM/PCM): the work does not meet expectations	The Terrain Response Control Module has detected that a component in the engine control module has operated abnormally or at an inopportune time. Engine Management System, Engine Control Module is unable to maintain normal Terrain Response operation, Terrain Response system enters default state. Engine management system malfunction. Engine control unit malfunction.	Check for engine control module DTCs using the manufacturer approved diagnostic system and refer to the DTC index for their meaning; correct the faults as necessary. Make sure the system is operating properly and the DTC does not re-set.
U0402-94	Incorrect data received from gearbox control unit: operation not as expected	The Terrain Response Control Module has detected that a component in the transmission control module has operated incorrectly or at an inopportune time. The transmission, gearbox control unit is unable to maintain normal operation of Terrain Response, the Terrain Response system goes into default state. Gearbox system malfunction. Gearbox control unit malfunction.	Check for transmission control module DTCs using the manufacturer approved diagnostic system and refer to the DTC index for their meaning; correct the faults as necessary. Make sure the system is operating properly and the DTC does not re-set.
U0415-94	Invalid data received from the anti-lock brake system (ABS) control unit: operation not as expected	The Terrain Response Control Module has detected that a component of the anti-lock brake system (ABS) control module is not operating as commanded or at the wrong time. Anti-lock Brake System: The Anti-lock Brake System control unit is unable to maintain normal Terrain Response operation, the Terrain Response system enters a default state. Anti-lock braking system malfunction. Malfunction of the anti-lock braking system control unit.	Using the manufacturer's recommended diagnostic system, check the anti-lock brake system control module for DTCs and refer to the appropriate DTC index. Repair as necessary. Verify that the system is functioning normally and that the DTC is no longer stored. The anti-lock brake system control module is likely to be faulty. Check and install a new anti-lock brake system control module if necessary - see the note on installing a new module/component at the beginning of the DTC index.
U0437-94	Invalid data received from rear differential control unit: operation not as expected	The Terrain Response control module has detected that a component in the rear differential control module is not operating as commanded or at the wrong time. Rear Differential System: The rear differential control unit is unable to maintain normal Terrain Response operation, the Terrain Response system enters a default state. Rear differential system malfunction. Rear differential control unit malfunction.	Check for DTCs for the rear differential control module using the manufacturer approved diagnostic system and refer to the DTC index for their meaning; repair as necessary. Verify that the system is functioning normally and that the DTC is no longer logged. Possibly a faulty rear differential unit. Check and install the rear differential unit if necessary - see the note on installing a new unit/component at the beginning of the DTC index.
U2012-4A	Vehicle Configuration Parameter(s): Inappropriate Component Installed	The Terrain Response control unit has detected a discrepancy between the connected component and the expected component. The vehicle configuration is not set up correctly. The installed components do not match the vehicle configuration.	Using the manufacturer approved diagnostic system, check the vehicle configuration file and correct if necessary. Check if the installed components match the vehicle configuration and correct if necessary. Verify that the system is functioning normally and that the DTC is no longer logged.