P1680

DTC P1680

DESCRIPTION
This diagnostic applies to internal microprocessor integrity conditions within the engine control module (ECM). This diagnostic also addresses if the ECM is not programmed.

DTC DESCRIPTOR
This Diagnostic procedure supports the following DTCs:
- DTC P0602 Control Module Not Programmed
- DTC P1621 Control Module Long Term Memory Performance
- DTC P2610 Control Module Ignition Off Timer Performance

CONDITION FOR RUNNING THE DTC
- The ignition is ON.
- DTC P0602, P1621, and P2610 run continuously once the above condition is met.

CONDITIONS FOR SETTING THE DTC
- DTC P0602 and DTC 1621 set when an error is detected in the electrically erasable programmable read only memory (EEPROM) data readout.
- DTC P2610 sets when there is a discrepancy of 500 seconds or more between the EONV timer and the PCM internal clock.

ACTION TAKEN WHEN THE DTC SETS
- The PCM illuminates the malfunction indicator lamp (MIL).
- The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame buffer.

CONDITIONS FOR CLEARING THE MIL/DTC
- The MIL turns OFF after 3 consecutively passing trips without a fault present.
- A history DTC clears after 40 consecutive warm-up cycles without a fault.
- Perform the scan tool Clear DTC Information function.

DIAGNOSTIC AIDS
Check the PCM for water contamination. Water entering the PCM can cause damage and corrosion to the circuit boards and to internal components. Repair the source of the water entry before the installation of a replacement PCM. A DTC P0602 or DTC P1621 can set if an incorrect PCM is installed in the vehicle. Install the correct PCM according to the vehicle and/or the engine type and equipment options.

TEST DESCRIPTION

Steps 1-8:

The numbers below refer to the step numbers in the diagnostic table.
1. The Diagnostic System Check-Computers and Control Systems prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
2. A DTC P0602 indicates the PCM is not programmed.
5. Attempt to program the PCM. If the PCM fails to program a second time, replace the PCM.