Test Description

WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

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

1: The Diagnostic System Check - Vehicle prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
4: This step determines if there is a condition with the control circuit of the main relay. If the control circuit of the main relay is open, the relay will not click ON and OFF when you remove and install the relay.
13: After replacing the PCM a new minimum throttle position and idle speed must also be established.

DTC P0685

Step	Action	Yes	No
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views
1	Did you perform the Diagnostic System Check - Vehicle?	Go to Step 2	Go to Diagnostic System Check - Vehicle
2	Inspect for an open ECM/CAM fuse. Is the fuse OK?	Go to Step 3	Go to Step 10
3	Swap the main relay with the cooling fan relay. Turn ON the ignition, with the ignition OFF. Does the scan tool communicate with the powertrain control module (PCM)?	Go to Step 12	Go to Step 4
4	Remove and install the main relay several times while listening for a clicking sound from the relay. Does the relay click when removing and installing the relay?	Go to Step 5	Go to Step 7
5	Remove the main relay. Probe the B+ supply circuit, switch side of the relay, at the underhood fuse block with a test lamp connected to a good ground. Refer to the Relay Cavity Identification table under Diagnostic Aids in this test. Does the test lamp illuminate?	Go to Step 6	Go to Step 11
6	Test the ignition 1 voltage supply circuit of the main relay between the ECM/CAM fuse and the PCM for an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?	Go to Step 14	Go to Step 9
7	Remove the main relay. Probe the B+ supply circuit, coil side of the relay, at the underhood fuse block with a test lamp connected to a good ground. Refer to the Relay Cavity Identification table under Diagnostic Aids in this test. Does the test lamp illuminate?	Go to Step 8	Go to Step 11
8	Turn OFF the ignition. Test the control circuit of the main relay for an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?	Go to Step 14	Go to Step 9
9	Test for an intermittent and for a poor connection at PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?	Go to Step 14	Go to Step 13
10	Repair the short to ground in the ignition 1 voltage circuit between the ECM/CAM fuse and the PCM. Refer to Wiring Repairs . Replace the fuse as necessary. Did you complete the repair?	Go to Step 14	-
11	Repair the short to ground or open in the B+ supply circuit of the main relay. Refer to Wiring Repairs . Did you complete the repair?	Go to Step 14	-
12	Replace the main relay. Did you complete the repair?	Go to Step 14	-
13	Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Perform the idle learn procedure. Refer to Idle Learn . Did you complete the replacement?	Go to Step 14	-
14	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 2	Go to Step 15
15	Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?	Go to Diagnostic Trouble Code (DTC) List - Vehicle	System OK