CAUSE D - CAN LO SHORTED TO UNSWITCHED OR SWITCHED BATT +
PROCEDURE OR ACTION:
1. Ensure truck power is OFF.
2. Ensure disconnection of EPR, ECM, and engine to main harness connector that carries the CAN circuit.
3. Change DMM to volts scale.
4. At the EPR connector, measure voltage between the Can Lo circuit and a clean vehicle ground.
Is voltage approximately system voltage?
YES: CAN Lo wire is shorted to a unswitched battery circuit. Locate and repair/replace open wire/connection.
See Wire Harness Repair 2200SRM1128.
NO: Go to Step 5.
5. Turn truck power ON.
6. Repeat Step 4.
Is voltage approximately system voltage?
YES: CAN Lo wire is shorted to a switched battery circuit. Locate and repair/replace open wire/connection.
See Wire Harness Repair 2200SRM1128.
NO: Go to Cause E.
CAUSE E - EPR FAILURE
PROCEDURE OR ACTION:
1. Ensure truck power is OFF.
2. Replace EPR. See LPG Fuel System 0900SRM1125 and Wire Harness Repair 2200SRM1128. For GM
5.7L LPG and GM 4.3L LPG engines with PSI, see LPG Fuel System 0900SRM1433 or LPG Fuel System,
GM 4.3L Engine With PSI 0900SRM1556.
3. Repeat Component Operational Check.
Does DTC reoccur?
YES: Repeat Cause A through Cause D
NO: Problem is corrected. Resume operation.
END POSSIBLE CAUSES