Conditions for Clearing the MIL/DTC
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.
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.
DTC P0403
| Step | Action | 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 |
|
Go to Step 3 | Go to Intermittent Conditions |
| 3 |
|
Go to Step 4 | Go to Step 6 |
| 4 |
IMPORTANT:
The low control circuit of the EGR valve normally has near ignition voltage present. Test the low control circuit for a short to all other voltage circuits from the engine control module (ECM). Test the low control circuit of the EGR valve 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 10 | Go to Step 5 |
| 5 | Test the EGR motor High Control Circuit and low control circuit for a short to ground. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
Go to Step 10 | Go to Step 7 |
| 6 | Test for shorted terminals and poor connections at the EGR valve. 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 10 | Go to Step 8 |
| 7 | Test for shorted terminals and poor connections at the ECM. 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 10 | Go to Step 9 |
| 8 | Replace the EGR valve. Refer to Exhaust Gas Recirculation (EGR) Valve Replacement
. Did you complete the replacement? |
Go to Step 10 | - |
| 9 | Replace the ECM. Refer to Engine Control Module (ECM) Replacement
. Did you complete the replacement? |
Go to Step 10 | - |
| 10 |
|
Go to Step 2 | Go to Step 11 |
| 11 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? |
Go to Diagnostic Trouble Code (DTC) List | System OK |