Circuit Description
The normally-open stop lamp switch supplies battery voltage to the ABS control module when the brake pedal is depressed.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC C0161 ABS/TCS Brake Switch Circuit
Conditions for Setting the DTC
Important: When DTC C0161 sets, the ABS control module will NOT disable the ABS, the traction control system (TCS), and the dynamic rear proportion (DRP).
The DTC will set if the ABS control module detects an open in circuit 20.
Diagnostic Aids
Inspect the wiring, the components, and the connectors for the following:
| • | Proper connection |
| • | Backed-out terminals |
| • | Broken connector locks |
| • | Corrosion in the connectors/terminals |
| • | Burned, chafed, or pinched wiring |
| • | A broken wire inside the insulation |
| • | Loose components |
| • | Both brake lamp bulbs burned out |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This DTC detects an open stop lamp switch signal circuit from the stop lamp side of the splice pack to the electronic brake control module (EBCM).
-
The EBCM sources 5 volts on the stop lamp switch signal circuit. This small voltage has a ground path through the stop lamp bulbs. This DTC sets if the path to ground is open.
Step | Action | Yes | No |
|---|---|---|---|
Connector End View Reference: Antilock Brake System Connector End Views or Lighting Systems Connector End Views in Lighting Systems | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Does the Brake Switch Status parameter display Applied? | Go to Step 4 | Go to Step 3 |
Test the signal circuit of the stop lamp switch for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 7 | |
Press the brake pedal. Are all of the stop lamps OFF? | Go to Step 5 | Go to Diagnostic Aids | |
5 | Test the feed circuit of the stop lamps for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 6 |
6 | Test the ground circuit of the stop lamps for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Diagnostic Aids |
7 | Inspect for poor connections at the harness connector of the electronic brake control module (EBCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 8 |
8 | Replace the EBCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | Go to Step 9 | -- |
9 |
Does the DTC reset? | Go to Step 2 | System OK |
