DTC C1850-14

DTC C1850-14  : Fail Safe Relay Stuck OFF

NOTE:  Before you troubleshoot, review the General Troubleshooting Information .

DTC (Real Time AWD)

1. Problem verification (with engine idling)

   -1. Turn the vehicle to the ON mode.

   -2. Clear the DTC with the HDS.

   -3. Turn the vehicle to the OFF (LOCK) mode.

   -4. Enter the maintenance mode and start the engine .

   -5. Check for DTCs with the HDS.

   DTC Description	DTC	Freeze Frame
   C1850-14 Fail Safe Relay Stuck OFF

   Is DTC C1850-14 indicated?

   YES 

   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. Fuse check

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

   -2. Check the following fuse.

   Fuse

   No. A4-3

   Is the fuse OK?

   YES 

   The fuse is OK. Reinstall the fuse, then go to step 3.

   NO 

   Replace the fuse. If the fuse blows again, repair a short to ground in the No. A4-3 fuse circuit, then go to step 4

3. Open wire check (+B_E-DPS line)

   -1. Disconnect the following connector.

   AWD control unit 24P connector

   -2. Turn the vehicle to the ON mode.

   -3. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode
   	AWD control unit 24P connector: disconnected
   Test point 1	AWD control unit 24P connector No. 2
   Test point 2	Body ground

   Is there battery voltage?

   YES 

   The +B_E-DPS 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 , and recheck. 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 +B_E-DPS wire between the No. A4-3 fuse and the AWD control unit.

4. Determine possible failure area (MH line, others)

   -1. Measure the resistance between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	AWD control unit 24P connector: disconnected
   Test point 1	AWD control unit 24P connector No. 1

   Test point 2

   Body ground

   Is there 1.0 Ω or less?

   YES 

   Go to step 5.

   NO 

   Go to step 6.

5. Rear differential pump motor internal shorted check

   -1. Disconnect the following connector.

   Rear differential pump motor 2P connector

   -2. Measure the resistance between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	AWD control unit 24P connector: disconnected
   	Rear differential pump motor 2P connector: disconnected
   Test point 1	Rear differential pump motor 2P connector (male terminals) No. 2:
   Test point 2	Body ground

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

   Is there 1.0 Ω or less?

   YES 

   Replace the rear differential pump motor .

   NO 

   The rear differential pump motor is OK. Repair a short to ground in the MH wires between the rear differential pump motor and the AWD control unit.

6. Rear differential pump motor internal shorted check

   -1. Disconnect the following connector.

   Rear differential pump motor 2P connector

   -2. On the pump motor side, measure the resistance between test points 1 and 2.

   Test condition	Vehicle OFF mode
   	AWD control unit 24P connector: disconnected
   	Rear differential pump motor 2P connector: disconnected
   Test point 1	Rear differential pump motor 2P connector (male terminals) No. 1:
   Test point 2	Rear differential pump motor 2P connector (male terminals) No. 2:

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

   Is there 1.0 MΩ or more?

   YES 

   The rear differential pump motor 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 , and recheck. If the symptom/indication goes away with a known-good AWD control unit, replace the original AWD control unit .

   NO 

   Replace the rear differential pump motor .