DTC 73

DTC 73

Step 1-8:

Circuit Description
Spark retard is simultaneously controlled by the Electronic Brake Control Module (EBCM) and the powertrain control module (PCM). The PCM supplies a 12 volt pushup voltage. This voltage is monitored by the PCM, the EBCM requests spark retard by pulling the voltage low.

Conditions for Running the DTC
DTC 65 can be set anytime the ignition switch is in the ON position.

Conditions for Setting the DTC
The EBCM detects one of the following conditions in the spark retard circuitry:
- An open or high resistance
- A short to ground
- A short to voltage

Action Taken When the DTC Sets
- The EBCM disables the traction control system for the remainder of the ignition cycle.
- The TRAC OFF warning indicator turns ON.

Conditions for Clearing the DTC
The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used.

Diagnostic Aids
Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.

The following are possible causes of the malfunction:
- An open, high resistance, or a short in the spark retard circuit
- An internal EBCM malfunction
- An internal PCM malfunction

If an intermittent malfunction exists, refer to Testing for Intermittent and Poor Connections Diagnostic Aids.

Test Description
The numbers in the image refer to step numbers 0!1 the diagnostic table.
3. This step tests the voltage of spark retard circuit of the EBCM.
4. This step tests the spark retard circuit of the EBCM or a short to voltage.
5. This step tests the spark retard circuit of the EBCM or an open, high resistance or short to ground.