For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provide an overview of each diagnostic category.

### DTC Descriptors

DTC P1793 72: Wheel Speed Signal (Invalid Serial Data Received)

### Circuit/System Description

The electronic brake control module (EBCM) sends wheel speed sensor information to the engine control module (ECM). The data is sent to the ECM through a GMLAN serial data bus.

### Conditions for Running the DTC

The ignition is ON.

### Conditions for Setting the DTC

The ECM detects an invalid signal from the EBCM.

### Action Taken When the DTC Sets

DTC P1793 is a Type C DTC.

### Conditions for Clearing the DTC

DTC P1793 is a Type C DTC.

### Reference Information

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

### Circuit/System Testing

1. Observe the Freeze Frame/Failure Records with a scan tool.
2. Clear the DTCs with a scan tool.
3. Ignition OFF for 30 seconds.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

⇒ | If DTC P1793 failed this ignition, replace the EBCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for EBCM replacement, setup, and programming.