Conditions for Clearing the MIL/DTC

WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
The DTC can be cleared by using the scan tool Clear DTC Information function.

DTC P1637

Step	Action	Value	Yes	No
Schematic Reference: Starting and Charging Schematics Connector End View Reference: Engine Controls Connector End Views in Engine Controls-5.7L, Power and Grounding Connector End Views in Wiring Systems, or Engine Electrical Connector End Views
1	Did you perform the Engine Electrical Diagnostic System Check?	-	Go to Step 2	Go to Diagnostic System Check - Engine Electrical
2	Install a scan tool. Turn ON the ignition, with the engine OFF. Wait 5 seconds. Start the engine. With a scant tool, monitor the DTC information for DTC P1637 in Engine Controls. Does the scan tool indicate that DTC P1637 has passed?	-	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems	Go to Step 3
3	Turn Off the engine. Disconnect the generator harness connector. Start the engine. Measure the voltage between the generator turn on signal circuit and ground. Does the voltage measure near the specified value?	5.0 V	Go to Step 5	Go to Step 4
4	Test the generator turn on signal circuit for a short or open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 11	Go to Step 5
5	Test the generator battery positive voltage sense circuit for a high resistance or open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 11	Go to Step 6
6	Test the generator battery positive voltage output circuit for a high resistance or open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 11	Go to Step 7
7	Inspect for poor connections at the harness connector of the generator. Refer to Connector Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 11	Go to Step 9
8	Inspect for poor connections at the harness connector of the PCM. 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 generator. Refer to Generator Replacement . Did you complete the replacement?	-	Go to Step 11	-
10	IMPORTANT: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement in Engine Controls 5.7L.Did you complete the repair?	-	Go to Step 11	-
11	Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset?	-	Go to Step 3	System OK