Description
The engine control module (ECM) has detected a failure in the communication circuitry.
Conditions for Setting the DTC
An error was detected in the EEPROM data readout.
Action Taken When the DTC Sets
| • | The ECM illuminates the malfunction indicator lamp (MIL). |
| • | The ECM 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 three consecutively passing trips without a fault present. |
| • | A History DTC clears after 40 consecutive warm-up cycles without a fault. |
| • | Use the scan tool Clear DTC Information function or disconnect the ECM battery feed in order to clear the DTC. |
Diagnostic Aids
Check the ECM for water contamination. Water entering the ECM 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 ECM.
Test Description
The numbers below refer to the step numbers in the Diagnostic Table.
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The Powertrain (OBD) System Check 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.
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This step determines if the fault is present. Replace the ECM if this DTC sets again.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | |||
|
Important: If the vehicle does not start, crank the engine in order to allow the DTC to set.
Does the scan tool indicate a DTC P0603? | -- | Go to Diagnostic Aids | ||
3 | Replace the ECM. Refer to Engine Control Module Replacement. Is the action complete? | -- | -- | |
4 |
Are any DTCs displayed on the scan tool? | -- | Go to the Applicable DTC Table | System OK |
