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Home >> Cadillac >> 2007 >> CTS Base, 2.8 T, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 157 (Antilock Brake System, Traction Control System & Stability Control System) >> Diagnostic Information and Procedures >> DTC C0121 >> Test Description
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Test Description

WARNING: This page is about a different car, the 2007 Cadillac SRX. However, it is still accessible from the selected car via links, so may be relevant.

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

  1. 2:  Determines whether the DTC is current.
DTC C0121

Step Action Values Yes No
Schematic Reference: Antilock Brake System Schematics 
Connector End View Reference: Antilock Brake System Connector End Views 
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Use the scan tool in order to clear the DTCs.
  4. With the scan tool, perform the Automated Test.
Does the DTC reset as a current DTC?
- Go to Step 3  Go to Testing for Intermittent Conditions and Poor Connections
3
  1. Remove the electronic brake control module (EBCM) from the brake pressure modulator valve (BPMV). Refer to Electronic Brake Control Module Replacement .
  2. Measure the resistance between each pump motor terminal and the housing of the BPMV.
Does the DMM display the specified value?
OL Go to Step 5  Go to Step 4 
4 Replace the electronic brake control module (EBCM) and the BPMV. Refer to Electronic Brake Control Module Replacement  and Brake Pressure Modulator Valve Replacement .
Did you complete the replacement?
- Go to Step 6  -
5 Replace the EBCM. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?
- Go to Step 6  -
6
  1. Use the scan tool in order to clear the DTCs.
  2. With the scan tool, perform the Automated Test.
Does the DTC reset?
- Go to Step 2  System OK