Engine Code

P0602-CHECKSUM ERROR

WHEN MONITORED
While the ignition is on.

SET CONDITION
A deviation between the ECM memory and a stored calibration.

POSSIBLE CAUSES
- Flash ECM
- ECM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

DIAGNOSTIC TEST

1. FLASH ECM
Using the scan tool, reflash the ECM with the proper calibration for the particular truck.

Q: Is the flash successful?

YES: Repair complete.
NO: Go To 2

2. ECM
With the scan tool, read DTCs.

Q: Did P0602 set after the reflash?

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