DTC C1840-12 (AWD) (2019 2020 2021)
DTC C1840-12 : Differential Fluid Pressure Sensor Circuit High Voltage
NOTE: Before you troubleshoot, review the General Troubleshooting Information .
| DTC Description | DTC | Freeze Frame |
|---|---|---|
| C1840-12 Differential Fluid Pressure Sensor Circuit High Voltage |
DTC (AWD)
- Determine possible failure area (electrical circuit problem, hydraulic circuit problem)
-1. Start the engine.
-2. Check the parameter(s) below with the HDS.
Signal Threshold Current conditions Values Unit Values Unit Voltage of the oil pressure sensor for rear differential More than 4.14 V Do the current condition(s) match the threshold?
YES
Go to step 3.
NO
Go to step 2.
- Problem verification
-1. Clear the DTC with the HDS.
-2. Turn the vehicle to the OFF (LOCK) mode.
-3. Turn the vehicle to the ON mode.
-4. Select the FUNCTION TEST in the AWD WITH INTELLIGENT CONTROL with the HDS.
-5. Do the OIL PRESSURE CONTROL TEST with the HDS .
Oil Pressure Control Test
Is the test result OK?
YES
Intermittent failure, the system is OK at this time. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.
NO
The failure is duplicated. Follow the instructions indicated on the HDS according to the test result .
- Determine possible failure area (short to power in PS line, others)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Disconnect the following connector.
Rear differential fluid pressure sensor 3P connector -3. Turn the vehicle to the ON mode.
-4. Measure the voltage between test points 1 and 2.
Test condition Vehicle ON mode Rear differential fluid pressure sensor 3P connector: disconnected Test point 1 Rear differential fluid pressure sensor 3P connector (female terminals) No. 1: Test point 2 Rear differential fluid pressure sensor 3P connector (female terminals) No. 2: Is there about 4.14 V or more?
YES
Go to step 4.
NO
Go to step 7.
- Shorted wire check (PS line to power)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Disconnect the following connector.
AWD control unit 24P connector -3. Turn the vehicle to the ON mode.
-4. Measure the voltage between test points 1 and 2.
Test condition Vehicle ON mode Rear differential fluid pressure sensor 3P connector: disconnected AWD control unit 24P connector: disconnected Test point 1 Rear differential fluid pressure sensor 3P connector (female terminals) No. 2: Test point 2 Body ground Is there about 0.5 V or more?
YES
Repair a short to power in the PS wire between the rear differential fluid pressure sensor and the AWD control unit.
NO
The PS wire is OK. Go to the 5.
- Shorted wire check (PS line to SVCC line)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Rear differential fluid pressure sensor 3P connector: disconnected AWD control unit 24P connector: disconnected Test point 1 Rear differential fluid pressure sensor 3P connector (female terminals) No. 2: Test point 2 Rear differential fluid pressure sensor 3P connector (female terminals) No. 3: Is there continuity?
YES
Repair a short in the PS wire to the SVCC wire between the rear differential fluid pressure sensor and the AWD control unit.
NO
The PS wire and the SVCC wire are OK. Go to step 6.
- Rear differential fluid pressure sensor check
-1. Connect the following connector.
AWD control unit 24P connector -2. Connect terminals A and B with a jumper wire.
Terminal A Rear differential fluid pressure sensor 3P connector (female terminals) No. 1: Terminal B Rear differential fluid pressure sensor 3P connector (female terminals) No. 2: -3. Turn the vehicle to the ON mode.
-4. Check the parameter(s) below with the HDS.
Signal Threshold Current conditions Values Unit Values Unit Voltage of the oil pressure sensor for rear differential Less than 0.1 V Do the current condition(s) match the threshold?
YES
Replace the rear differential fluid pressure sensor .
NO
The rear differential fluid pressure sensor is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting or substitute a known-good AWD control unit , then recheck. If this DTC goes away and the AWD control unit was substituted, replace the original AWD control unit .
- Determine possible failure area (open in PS line, others)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Connect terminals A and B with a jumper wire.
Terminal A Rear differential fluid pressure sensor 3P connector (female terminals) No. 2: Terminal B Body ground -3. Turn the vehicle to the ON mode.
-4. Check the parameter(s) below with the HDS.
Signal Threshold Current conditions Values Unit Values Unit Voltage of the oil pressure sensor for rear differential Less than 0.1 V Do the current condition(s) match the threshold?
YES
Go to step 9.
NO
Go to step 8.
- Open wire check (PS line)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Remove the jumper wire.
-3. Disconnect the following connector.
AWD control unit 24P connector -4. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Rear differential fluid pressure sensor 3P connector: disconnected AWD control unit 24P connector: disconnected Test point 1 Rear differential fluid pressure sensor 3P connector (female terminals) No. 2: Test point 2 AWD control unit 24P connector No. 21 Is there continuity?
YES
The PS wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting or substitute a known-good AWD control unit , then recheck. If this DTC goes away and the AWD control unit was substituted, replace the original AWD control unit .
NO
Repair an open in the PS wire between the rear differential fluid pressure sensor and the AWD control unit.
- Open wire check (SG line)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Remove the jumper wire.
-3. Disconnect the following connector.
AWD control unit 24P connector -4. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Rear differential fluid pressure sensor 3P connector: disconnected AWD control unit 24P connector: disconnected Test point 1 Rear differential fluid pressure sensor 3P connector (female terminals) No. 1: Test point 2 AWD control unit 24P connector No. 11 Is there continuity?
YES
The SG wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting or substitute a known-good AWD control unit , then recheck. If this DTC goes away and the AWD control unit was substituted, replace the original AWD control unit .
NO
Repair an open in the SG wire between the rear differential fluid pressure sensor and the AWD control unit.