DTC C1840-14 (47-02) (AWD) (2016 2017 2018)

DTC C1840-14  : Differential Fluid Pressure Sensor Circuit Low Voltage

NOTE:  Before you troubleshoot, review the General Troubleshooting Information for the AWD with intelligent control system .

DTC (AWD)

1. Problem verification

   -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	Less than 0.34	V

   Do the current condition(s) match the threshold?

   YES 

   The failure is duplicated. Go to step 2.

   NO 

   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.

2. Determine possible failure area (PS1 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. 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	About 5	V

   Do the current condition(s) match the threshold?

   YES 

   Go to step 4.

   NO 

   Go to step 3.

3. Shorted wire check (PS1 line)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Disconnect the following connector.

   AWD control unit 24P connector

   -3. 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 No. 2
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   Repair a short to ground or the SG wire in the PS1 wire between the rear differential fluid pressure sensor and the AWD control unit.

   NO 

   Update the AWD control unit if it does not have the latest software , or substitute a known-good AWD control unit , and recheck. If the symptom/indication goes away with the updated AWD control unit, troubleshooting is complete. If the symptom/indication goes away with a known-good AWD control unit, replace the original AWD control unit .

4. Determine possible failure area (rear differential fluid pressure sensor, SVCC line)

   -1. 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 No. 1
   Test point 2	Rear differential fluid pressure sensor 3P connector No. 3

   Courtesy of HONDA, U.S.A., INC.

   Is there about 5 V?

   YES 

   Replace the rear differential fluid pressure sensor .

   NO 

   Go to step 5.

5. Open wire check (SVCC line)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Disconnect the following connector.

   AWD control unit 24P connector

   -3. 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 No. 3
   Test point 2	AWD control unit 24P connector No. 20

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   Update the AWD control unit if it does not have the latest software , or substitute a known-good AWD control unit , and recheck. If the symptom/indication goes away with the updated AWD control unit, troubleshooting is complete. If the symptom/indication goes away with a known-good AWD control unit, replace the original AWD control unit .

   NO 

   Repair an open in the SVCC wire between the rear differential fluid pressure sensor and the AWD control unit.