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Home >> Pontiac >> 2004 >> GTO Standard >> Repair and Diagnosis >> Brakes >> Antilock Brake System And Traction Control System >> Diagnostic Information and Procedures >> DTC 73 >> Test Description
July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

Test Description

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

  1. 3:  This step tests the voltage of spark retard circuit of the EBCM.
  2. 4:  This step tests the spark retard circuit of the EBCM or a short to voltage.
  3. 5:  This step tests the spark retard circuit of the EBCM or an open, high resistance or short to ground.
DTC 73

Step Action Value(s) Yes No
Schematic Reference:  ABS Schematics  
Connector End View Reference:  ABS Connector End Views  
1 Did you perform A Diagnostic System Check - ABS? - Go to Step 2  Go to Diagnostic System Check - ABS 
2 Is DTC 73 set as a current DTC? - Go to Step 3  Go to Diagnostic Aids
  1. Turn OFF the ignition.
  2. Disconnect the electronic brake control module (EBCM) harness connector.
  3. Turn ON the ignition, with the engine running.
  4. Measure the voltage between the SPK retard circuit of the EBCM and a good ground. Refer to Circuit Testing in Wiring Systems.
Does the voltage measure as specified?
Battery Voltage Go to Step 4  Go to Step 5 
Test the SPK retard circuit of the EBCM for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
- Go to Step 8  Go to Step 6 
Test the SPK retard circuit of the EBCM for an open, high resistance or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
- Go to Step 8  Go to Step 7 
6 Replace the EBCM. Refer to Electronic Brake Control Module Replacement .
Did you complete the replacement?
- Go to Step 8  -
7 Replace the powertrain control module (PCM). Refer to Powertrain Control Module (PCM) Replacement in Engine Controls - 5.7L.
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