For 1990-2009 cars

### Circuit Description

This DTC is used to identify the condition of traction control system (TCS) switch and circuit. The ignition voltage is passing through fuse F9, terminal 2 of connector C202, TCS switch and terminal 14 of EBCM.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C1503 Traction Control Switch Circuit

### Conditions for Running the DTC

Ignition is in the ON position.

### Conditions for Setting the DTC

• | Out of adjustment or shorted TCS switch contact

• | TCS switch circuit shorted to battery

• | Internal EBCM fault

### Action Taken When the DTC Sets

• | DTC C1503 is stored.

• | TCS disabled, TCS warning lamp turns on.

### Conditions for Clearing the DTC

If the conditions that set DTC C1503 are no longer presents, the DTC can be cleared by scan tool.

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Antilock Brake System Schematics Connector End View Reference: Component Connector End Views
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Check fuse F9. Is the fuse OK? | Go to Step 4 | Go to Step 3
3 |

1. Replace the fuse.
2. Perform the Diagnostic System Check - Vehicle .

Did the DTC Reset?

Go to Step 4

Go to Step 8

4 | Check the terminal 2 of connector C202, wiring harness and terminal 14 of EBCM. Did you find any open or short circuit of the wiring harness or abnormal terminal forms? | Go to Step 5 | Go to Step 6
5 | Repair the open or short circuit of the wiring harness and terminals. Did you complete the repair? | Go to Step 8 | --
6 |

1. Replace the traction control system (TCS) switch.
2. Perform the Diagnostic System Check - Vehicle .

Did the DTC Reset?

Go to Step 7

Go to Step 8

7 | Replace the EBCM. Did you complete the replacement? | Go to Step 8 | --
8 |

1. Use the scan tool in order to clear the DTCs.
2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK