Diagnostic Aids
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
If the engine starts, the ignition relay control circuit is shorted to power intermittently.
DTC P0612
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views |
||||
| 1 | Did you perform the Diagnostic System Check-Engine Controls? | - | Go to Step 2 | Go to Diagnostic System Check - Engine Controls |
| 2 | Attempt to start the engine. Does the engine start? |
- | Go to Diagnostic Aids | Go to Step 3 |
| 3 |
|
- | Go to Step 5 | Go to Step 4 |
| 4 | Using a DMM, measure the resistance of the coil circuit of the ignition 1 relay. Does the resistance measure within the specified range? |
60-80 ohm | Go to Step 7 | Go to Step 6 |
| 5 | Repair the short to battery or ignition voltage on the ignition 1 relay control circuit. Refer to Wiring Repairs
in Wiring Systems. Did you complete the repair? |
- | Go to Step 8 | - |
| 6 | Replace the ignition 1 relay. Did you complete the replacement? |
- | Go to Step 8 | - |
| 7 | Replace the ECM. Refer to Engine Control Module (ECM) Replacement
. Did you complete the replacement? |
- | Go to Step 8 | - |
| 8 |
|
- | Go to Step 9 | Go to Step 2 |
| 9 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? |
- | Go to Diagnostic Trouble Code (DTC) List | System OK |