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 provides an overview of each diagnostic category.

### DTC Descriptor

DTC C0720 71: Engine Torque Management Feedback Signal Invalid Data

### Circuit/System Description

The suspension control module receives high speed controller area network (CAN) message inputs from the engine control module (ECM) identifying the actual engine torque. The suspension control module utilizes this signal to control the vehicle ride characteristics.

### Conditions for Running the DTC

System voltage is between 9 and 16 V

### Conditions for Setting the DTC

The suspension control module received invalid serial data from the ECM.

### Action Taken When the DTC Sets

The electronic suspension control is disabled for the duration of the ignition cycle.

### Conditions for Clearing the DTC

• | The condition for setting the DTC is no longer present.

• | A history DTC will clear after 41 consecutive malfunction-free ignition cycles.

### Reference Information

#### Schematic Reference

Electronic Suspension Control Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Electronic Suspension Control Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Testing

1. Verify that no DTCs are present in the ECM.

⇒ | If any DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle to diagnose that DTC prior to this diagnostic.

2. Replace the K19 Electronic Suspension Control (ESC) Module and verify the DTC does not reset.

⇒ | If the DTC resets replace the K20 Engine Control Module (ECM).

### Repair Instructions

• | Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Control Module References for control module replacement, setup and programming