DTC C1840-14 (47-02): Differential Fluid Pressure Sensor Circuit Low Voltage

WARNING: This page is about a different variant/trim than selected.

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

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

DTC (Real Time AWD)

Problem verification

- 1. Start the engine.

- 2. Check the parameter(s) below with the HDS.

Signal	Threshold		Current Conditions
Signal	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.

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.

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
Signal	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.

Go to step 3.

Shorted wire check (PS1 line)

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

- 2. Disconnect the following connector.

Real time 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
	Real time 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 real time AWD control unit.

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

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 REMOVAL & INSTALLATION(AWD) .

Go to step 5.

Open wire check (SVCC line)

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

- 2. Disconnect the following connector.

Real time 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
	Real time AWD control unit 24P connector: disconnected
Test point 1	Rear differential fluid pressure sensor 3P connector No. 3
Test point 2	Courtesy of HONDA, U.S.A., INC.

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

Is there continuity?

YES

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