For 1990-2009 cars

### Circuit Description

The vehicle speed sensor (manual transmission) or the transmission control module (TCM) transmits a processed vehicle speed signal (VSS) to the speed sensitive power steering (SSPS) control module. The SSPS control module uses the speed signal and the characteristic curve programmed in the microprocessor to determine the electric current variable for the power steering fluid flow control valve actuator.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C1212 Vehicle Speed Sensor (VSS) Circuit

### Conditions for Running the DTC

• | The engine is running.

• | Scan tool Idle Switch parameter is indicating OFF.

### Conditions for Setting the DTC

The power steering control module detects that the VSS is no longer present.

### Action Taken When the DTC Sets

• | Power steering assist will default to full steering assist.

• | The SSPS control module will store a DTC C1212 in memory.

### Conditions for Clearing the DTC

• | The SSPS warning lamp will turn OFF when conditions for the fault are no longer present.

• | Use a scan tool in order to clear the DTC.

### Diagnostic Aids

Check for the following conditions if a history or intermittent DTC is indicated.

• | A poor connection at the SSPS control module. Inspect the harness connectors for backed out terminals, improper mating, improperly formed or damaged terminals, and poor terminal to wire connections.

• | A damaged wiring harness. Inspect the wiring harness for damages. If the wiring harness appears to be in good condition, observe the display on the DMM while moving the connectors and wiring harnesses related to the actuator. A change in the DMM display during the test will indicate the location of the fault.

• | For additional information, refer to Testing for Intermittent Conditions and Poor Connections .

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Steering Assist Schematics Connector End View Reference: Steering Assist Connector End Views
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Install a scan tool.
2. Raise the vehicle drive wheels. Refer to Lifting and Jacking the Vehicle .
3. Start the engine.
4. Place the transmission into drive for an automatic transmission or third gear for a manual transmission.
5. With the scan tool, observe the Vehicle Speed parameter in the Speed Sensitive Steering data list.

Does the Vehicle Speed parameter match the speedometer display?

Go to Step 6

Go to Step 3

3 | Test for an open or poor connection on the vehicle speed circuit of the speed sensitive power steering (SSPS) control module. Refer to Testing for Continuity and Testing for Intermittent Conditions and Poor Connections . Did you find and correct the condition? | Go to Step 6 | Go to Step 4
4 | Test for a poor connection on the ground circuit of the SSPS control module. Refer to Testing for Continuity and Testing for Intermittent Conditions and Poor Connections . Did you find and correct the condition? | Go to Step 6 | Go to Step 5
5 | Replace the SSPS control module. Refer to Power Steering Control Module Replacement . Did you complete the replacement? | Go to Step 6 | --
6 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2