U1601

U1601-ECU APPLICATION SOFTWARE CODE 1 MISSING OR CORRUPTED
For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.
Theory of Operation

If the Engine Control Module (ECM) does not have a calibration installed, or has an unapproved calibration installed then the ECM will be in a ROM boot state. The ECM will have power but no approved software to allow the vehicle to be started and driven. No further diagnostics of the ECM will be available at this time. This code will be cleared when the ECM has the correct approved calibration installed.

- When Monitored:
Ignition on.

- Set Condition:
The Engine Control Module (ECM) is in ROM boot mode.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. NEW ENGINE CONTROL MODULE (ECM)
1. If the ECM was replaced and not programmed this DTC will set.
2. With a scan tool clear DTCs.

Has the ECM been replaced on this vehicle?

Yes

- Flash the Engine Control Module (ECM) with the correct software.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 2

2. DOWNLOAD FAILED
1. If the vehicle lost battery power or the scan tool was disconnected while performing a flash, this DTC will set.

Was a software download interrupted during the download process?

Yes

- Reflash the Engine Control Module.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 3

3. UNAPPROVED SOFTWARE INSTALLED
1. Unapproved software programmed into the Engine Control Module is not a warrantable repair.

If tests one and two do not apply, the vehicle has been programmed with unapproved software.

Yes

- Reflash the Engine Control Module with the correct software.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.