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 P2142

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	Start the engine Run the engine at 1,000 RPM. Command the EGR throttle valve solenoid ON and OFF with a scan tool. Does the tone of the engine change when the EGR throttle valve solenoid is commanded ON and OFF with a scan tool?	-	Go to Step 3	Go to Step 5
3	Turn OFF the ignition. Disconnect the ECM harness connector containing the EGR throttle valve vacuum solenoid control circuit. Connect a DMM between the EGR throttle valve vacuum solenoid control circuit and a good ground. Set the DMM to the 10 amp scale Turn ON the ignition with the engine OFF. Observe the DMM for 2 minutes. Does the current measure less than the specified value for the entire 2 minutes.	0.75 A	Go to Step 4	Go to Step 9
4	Turn OFF the ignition. Reconnect the ECM connector. Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition?	-	Go to Step 5	Go to Intermittent Conditions
5	Connect a test lamp between the control circuit of the EGR throttle valve vacuum control solenoid and the ignition 1 voltage circuit of the EGR throttle valve vacuum control solenoid. Command the EGR throttle valve solenoid ON and OFF with a scan tool. Does the test lamp turn ON and OFF when commanded with a scan tool?	-	Go to Step 7	Go to Step 6
6	Test the Control circuit of the EGR throttle valve vacuum control solenoid for a short to voltage. Refer to Testing for a Short to Voltage and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 11	Go to Step 8
7	Test for an intermittent and for a poor connection at the EGR throttle valve vacuum control solenoid. 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 11	Go to Step 9
8	Test for an intermittent and for a poor connection 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 11	Go to Step 10
9	Replace the EGR throttle valve vacuum control solenoid. Refer to Exhaust Gas Recirculation (EGR) Valve Throttle Solenoid Replacement . Did you complete the replacement?	-	Go to Step 11	-
10	Replace the ECM. Refer to Engine Control Module (ECM) Replacement . Did you complete the replacement?	-	Go to Step 11	-
11	Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition?	-	Go to Step 12	Go to Step 2
12	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