Test Description

The numbers below refer to the step numbers on the diagnostic table.

4: This step tests the control circuit for a shorted to voltage.

Step	Action	Values	Yes	No
Schematic Reference: Engine Controls Schematics Connect End View Reference: 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	Turn ON the ignition, with the engine OFF. Clear the DTC with a scan tool. Wait 30 seconds. Does DTC P1660 set?	-	Go to Step 4	Go to Step 3
3	Turn OFF the ignition for 30 seconds. Operate the vehicle within the Conditions for Running the DTC. Did the DTC fail this ignition?	-	Go to Step 4	Go to Intermittent Conditions
4	Turn OFF the ignition. Disconnect the engine control module (ECM). Turn ON the ignition, with the engine OFF. Probe the control circuit of the MIL with a test lamp connected to a good ground. Does the MIL illuminate?	-	Go to Step 5	Go to Step 6
5	Test for shorted terminals and poor connections at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?	-	Go to Step 8	Go to Step 7
6	Repair a short to voltage on the control circuit of the MIL. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?	-	Go to Step 8	-
7	Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement?	-	Go to Step 8	-
8	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. Did the DTC fail this ignition?	-	Go to Step 2	Go to Step 9
9	Are there any DTCs that have not been diagnosed?	-	Go to Diagnostic Trouble Code (DTC) List	System OK