COMPONENT OPERATIONAL CHECK
PROCEDURE OR ACTION:
1. Turn power to OFF for no less than 30 seconds, and then to ON to clear displayed DTC.
Does reported DTC reoccur?
YES: Go to Step 2.
NO: Problem not verified. Resume operation.
2. Conduct a quick visual inspection of all connectors/wiring associated with the displayed fault code.
Are any faults detected/observed?
YES: Repair/replace connector or wiring associated with faults found. See Electrical System 2200SRM1142.
NO: Go to Cause A.
CAUSE A - EPR SUPPLY/GROUND OPEN CIRCUIT
PROCEDURE OR ACTION:
1. Change DMM to ohms scale. Verify DMM zero reading.
2. Turn truck power ON.
3. At EPR harness connector, measure voltage between EPR supply pin (+) and EPR battery (-) ground.
Is voltage approximately system voltage?
YES: Go to Cause B.
NO: Go to Step 4.
4. At 10 Amp EPR fuse, measure voltage between both sides of the fuse and EPR connector ground.
Is voltage approximately equal to Batt Vdc on both sides of the fuse?
YES: EPR supply circuit or ground circuit is open between EPR connector and the EPR fuse/main engine
ground. Locate and repair/replace open wire/connection. See Wire Harness Repair 2200SRM1128.
NO: Go to Step 5.
5. Inspect harness between fuse and EPR connection for a short to ground/frame. Locate and repair/replace
shorted wire/connection. See Wire Harness Repair 2200SRM1128.
6. Replace fuse with correct current rated part.
7. Repeat Cause AStep 2
Is voltage approximately system voltage?
YES: Go to Cause B.
NO: Go to Step 8.
8. Refer to power distribution module mini-schematic and check all switched battery circuits for open circuits/
shorts to vehicle ground/frame. Follow procedures as outlined in DTC 522762-4. Locate and repair/replace
shorted wire/connection. See Wire Harness Repair 2200SRM1128