For 1990-2009 cars

### Circuit Description

The serial data link is a communication line between the EBCM and the Data Link Connector (DLC). When the module detects no messages and a high voltage on the Class 2 serial data circuit for approximately three seconds, C1213 is set.

### Conditions for Running the DTC

Voltage supplied to the module is in the normal operating voltage range (approximately 9 to 16 volts).

### Conditions for Setting the DTC

DTC C1213 can be set anytime the ignition is ON. A malfunction exists if the serial data circuit is shorted to voltage for approximately three seconds resulting in no communication to the EBCM.

### Action Taken When the DTC Sets

• | ABS remains functional.

• | No action towards the electronic brake control relay is taken.

• | No action towards the ABS warning indicator is taken.

### Conditions for Clearing the DTC

• | The condition for DTC C1213 is no longer present.

• | The use of the scan tool CLEAR DTCs function.

• | DTC C1213 clears after 100 drive cycles with no DTCs detected. A drive cycle consists of starting the vehicle, driving the vehicle over 16 km/h (10 mph), stopping and then turning the ignition off.

### Diagnostic Aids

The malfunction may be intermittent. Try performing the tests shown while "wiggling" wiring and connectors, this can often cause the malfunction to appear. DTC U1301 will likely be set along with DTC C1213.

DTC U1301 and DTC C1213 will only be able to be read as history codes since the scan tool uses the same serial data circuit. If the serial data circuit is shorted to voltage, no communication with the scan tool will be possible. Refer to Scan Tool Does Not Communicate with Electronic Brake Control Module in Data Link Communications.