P1652

P1652-J1850 SHORT TO GROUND

P1652 - J1850 Short To Ground:

WHEN MONITORED
While the ignition is on.

SET CONDITION
The ECM detects a short to ground on the J1850.

POSSIBLE CAUSES
- ECM
- (D25) J1850 shorted
- Communication

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test

1. ECM





Turn the ignition off.
Disconnect the ECM harness connectors.

NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance between the (D25) J1850 circuit in the ECM harness connector and battery negative.

Q: Is the resistance less than 10 Ohms?

YES: Go To 2
NO: Replace the ECM. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1

2. (D25) J1850 SHORTED





Measure the resistance between the (D25) J1850 circuit and all other circuits in both ECM connectors.

Q: Is the resistance greater than 100k ohms?

YES: Refer to the Body Diagnostic book Communications section.
NO: Repair (D25) J1850 shorted to another circuit. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1