DTC Troubleshooting: C1850-14 (44-50)
DTC C1850-14: Fail Safe Relay Stuck OFF
NOTE: Before you troubleshoot, review the General Troubleshooting Information.

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

1.
Problem verification (with engine idling):

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.
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:

Fuse check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Check the following fuse.
Fuse
No. A20 (20 A)
Location
Under-hood fuse/relay box

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. A20 (20 A) fuse circuit, then go to step 4
3.
Open wire check (+B E-DPS line):

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
     
     
     
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. A20 (20 A) fuse and the AWD control unit.?
4.
Determine possible failure area (MH line, others):

Determine possible failure area (MH line, others)
?1.
Check for continuity 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 continuity?

     
YES
     
     
     
Go to step 5.
     
NO
     
     
     
Go to step 6.
5.
Rear differential pump motor internal shorted check:

Rear differential pump motor internal shorted check
?1.
Disconnect the following connector.
Rear differential pump motor 2P connector

?2.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Real time 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


Is there continuity?

     
YES
     
     
     
     
NO
     
     
     
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:

Rear differential pump motor internal shorted check
?1.
Disconnect the following connector.
Rear differential pump motor 2P connector

?2.
Check for continuity 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:


Is there continuity?

     
YES
     
     
     
     
NO
     
     
     
Go to step 7.
7.
AWD control unit check:

AWD control unit check
?1.
On the AWD control unit side, check for continuity 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
AWD control unit 24P connector No. 1
Test point 2
AWD control unit 24P connector No. 3

Is there continuity?

     
YES
     
     
     
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 No. A20 (20 A) fuse.?