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Home >> Cadillac >> 2002 >> Escalade EXT >> Repair and Diagnosis >> External Pages >> Different car >> Section 986 (Antilock Brake System And Traction Control System) >> Diagnostic Information and Procedures >> DTC C0161: Wheel Speed Sensor Frequency Error >> Test Description
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Test Description

WARNING: This page is about a different car, the 2004 Pontiac Aztek and 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

  1. 3:  This DTC detects an open stop lamp switch signal circuit from the stop lamp side of the splice pack to the EBCM.
  2. 4:  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.
DTC C0161

Step Action Yes No
Schematic Reference:  ABS Schematics  
Connector End View Reference:  ABS Connector End Views   or  Lighting Systems Connector End Views  in Lighting Systems
1 Did you perform the ABS Diagnostic System Check? Go to Step 2  Go to Diagnostic System Check - ABS 
2
  1. Press the brake pedal.
  2. With the scan tool, observe the Brake Switch Status parameter in the ABS data list.
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 stoplamps 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 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 Electronic Brake Control Module Replacement .
Did you complete the replacement?
Go to Step 9  -
9
  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