DTC C1858-72 (71-02): Differential Fluid Pressure Deviation Low

NOTE:  Before you troubleshoot, HOW TO TROUBLESHOOT THE REAL TIME AWD SYSTEM (AWD) .

DTC (Real Time AWD)

1. Rear differential fluid level check

   - 1. Check the rear differential fluid level, and check for rear differential fluid leakage.

   Is the check result OK?

   YES 

   The rear differential fluid level is OK. Go to step 2.

   NO 

   Find and repair the source of the fluid leak then add recommended fluid - Refer to: REAR DIFFERENTIAL FLUID INSPECTION AND REPLACEMENT (4WD) or REAR DIFFERENTIAL FLUID INSPECTION AND REPLACEMENT (AWD) .

2. Problem verification (function test with HDS)

   - 1. Turn the vehicle to the ON mode.

   - 2. Select the FUNCTIONAL TEST in the REAL TIME AWD with the HDS.

   - 3. Do the OIL PRESSURE CONTROL TEST in the FUNCTIONAL TEST with the HDS.

   Oil Pressure Control Test

   Is fault code indicated?

   Fault code is not indicated

   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.

   Fault code 2-1 or 5-1 is indicated

   Go to step 3.

   Fault code 3-1 is indicated

   Go to step 4.

   Fault code except 2-1, 3-1, and 5-1 is indicated

   Go to step 5.

3. Hydraulic system check

   - 1. Select the ADJUSTMENT in the REAL TIME AWD with the HDS.

   - 2. Do the AIR BLEEDING in the ADJUSTMENT with the HDS.

   Air Bleeding

   Select the FUNCTIONAL TEST in the REAL TIME AWD with the HDS.

   - 4. Do the OIL PRESSURE CONTROL TEST in the FUNCTIONAL TEST with the HDS.

   Oil Pressure Control Test

   Is the test result OK?

   YES 

   Hydraulic system is OK at this time.

   NO 

   Replace the rear differential fluid - Refer to: REAR DIFFERENTIAL FLUID INSPECTION AND REPLACEMENT (4WD) or REAR DIFFERENTIAL FLUID INSPECTION AND REPLACEMENT (AWD) then do the rear differential fluid pressure sensor test and do the rear differential solenoid valve test . If they are OK, replace the rear differential assembly - Refer to: REAR DIFFERENTIAL REMOVAL & INSTALLATION(4WD) or REAR DIFFERENTIAL REMOVAL & INSTALLATION(AWD) .

4. Hydraulic system check

   - 1. Select the ADJUSTMENT in the REAL TIME AWD with the HDS.

   - 2. Do the AIR BLEEDING in the ADJUSTMENT with the HDS.

   Air Bleeding

   Select the FUNCTIONAL TEST in the REAL TIME AWD with the HDS.

   - 4. Do the OIL PRESSURE CONTROL TEST in the FUNCTIONAL TEST with the HDS.

   Oil Pressure Control Test

   Is the test result OK?

   YES 

   Hydraulic system is OK at this time.

   NO 

   Replace the rear differential fluid - Refer to: REAR DIFFERENTIAL FLUID INSPECTION AND REPLACEMENT (4WD) or REAR DIFFERENTIAL FLUID INSPECTION AND REPLACEMENT (AWD) then do the rear differential fluid pressure sensor test and do the rear differential solenoid valve test . If they are OK, replace the rear differential assembly - Refer to: REAR DIFFERENTIAL REMOVAL & INSTALLATION(4WD) or REAR DIFFERENTIAL REMOVAL & INSTALLATION(AWD) .

5. DTC check

   - 1. Select the FUNCTIONAL TEST in the REAL TIME AWD with the HDS.

   - 2. Do the OIL PRESSURE CONTROL TEST in the FUNCTIONAL TEST with the HDS three times.

   Oil Pressure Control Test

   Check for DTCs with the HDS.

   DTC Description	DTC	Freeze Frame

   Are there any DTCs?

   YES 

   Go to the indicated DTC's troubleshooting.

   NO 

   The system is OK at this time.