For 1990-2009 cars

### Circuit Description

The power steering control module (PSCM) receives a vehicle speed message via the serial data circuit from the powertrain control module (PCM), if equipped with a 2.0L engine (LSJ), or from the engine control module (ECM), if equipped with a 2.2L engine (L61) or a 2.4L engine (LE5). The ECM receives the vehicle speed message from the transmission control module (TCM), if equipped with an automatic transmission (MN5). The PSCM uses this vehicle speed message, and other inputs, to determine the desired amount of steering assist. At lower speeds, more assist is provided for easy turning during parking maneuvers. At higher speeds, less assist is provided for improved road feel and directional stability.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0000 Vehicle Speed Information Circuit

This vehicle has DTCs which include DTC symptoms. For more information on DTC symptoms, refer to DTC Symptom Description .

DTC Symptom | DTC Symptom Descriptor
--- | ---
71 | Invalid Serial Data Received

### Conditions for Running the DTC

• | The ignition is ON.

• | DTCs U2100, U2105, 2107, or U2109 are not set.

• | Power steering system voltage is between 6-16 volts.

### Conditions for Setting the DTC

The PSCM receives an invalid vehicle speed message from the PCM (LSJ) or the ECM (L61/LE5).

### Action Taken When the DTC Sets

• | DTC C0000 71 is stored in memory.

• | The driver information center (DIC) displays the POWER STEERING warning message.

• | Steering assist is set to a default level.

• | Poor return to center.

### Conditions for Clearing the DTC

• | A current DTC will clear when the malfunction is no longer present.

• | A history DTC will clear after 100 consecutive malfunction-free ignition cycles.

• | The DTC can be cleared by using a scan tool.

### Test Description

The number below refers to the step number on the diagnostic table.

1. This step tests for the presence of vehicle speed related DTCs in the control module where the vehicle speed message originates.

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Data Communication Schematics
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Turn ON the ignition, with the engine OFF.
2. With a scan tool, select both the Engine and Transmission/Transaxle Diagnostic Trouble Codes (DTC) DTC Display functions.

Does the scan tool indicate the presence of any vehicle speed related DTCs?

Go to Diagnostic Trouble Code (DTC) List - Vehicle

Go to Step 3

3 |

1. Use the scan tool in order to clear the DTC.
2. Operate the vehicle within the conditions for running the DTC.

Does DTC C0000 reset?

Go to Step 2

System OK