This doesn't pinpoint a single faulty part. The problem could stem from several sources, including:
* Wiring harness issues: Damaged, corroded, or loose wires in the harness connecting the ECM and TCM. This is a very common cause.
* Connectors: Poor connections at the ECM and/or TCM connectors themselves. Corrosion or loose pins are frequent culprits.
* ECM or TCM failure: Although less likely, a malfunctioning ECM or TCM could cause this code. This is usually diagnosed after checking the wiring and connectors.
* Power supply problems: Intermittent power to either module can disrupt communication.
* Data Bus Problems: A problem with the Controller Area Network (CAN) bus, the communication system the ECM and TCM use to talk to each other.
Troubleshooting Steps (in order):
1. Visually inspect the wiring harness: Look for any obvious damage, corrosion, or loose connections between the ECM and TCM. Pay close attention to areas where the harness might be prone to chafing or damage.
2. Inspect the connectors: Carefully examine the connectors at both the ECM and TCM. Look for corrosion, bent pins, or loose connections. Clean any corrosion you find with a contact cleaner.
3. Check for power and ground: Ensure both modules are receiving proper power and ground. Use a multimeter to verify.
4. Clear the code: After addressing any wiring or connection issues, clear the DTC (Diagnostic Trouble Code) using an OBD-II scanner and test drive the vehicle to see if the code returns.
If the code persists after checking the wiring and connections, further diagnosis may require a professional mechanic with specialized tools to check for CAN bus communication problems or to determine if the ECM or TCM is faulty. Replacing a module should only be done after thorough testing and verification as it's an expensive repair.
