11-09-2009, 10:30 PM
True Car Nut
Join Date: Sep 2008
Location: Arlington, WA
Cooling Fan Relay 2 Control Circuit
Output driver modules (ODMs) are used by the PCM to turn on many of the current-driven devices that are needed to control various engine and transaxle functions. Each ODM is capable of controlling up to 7 separate outputs by applying ground to the devices which the PCM is commanding on. Unlike the quad driver modules (QDMS) used in prior model years, ODM’* have the capability of diagnosing each output circuit individually. DTC P0480 indicates an improper voltage level has been detected on the output circuit, which controls the fan 2 relay.
- The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test was run and failed.
- The PCM will store the conditions, which were present when the DTC set as Freeze Frame Failure Records Data.
Check for the following conditions:
- An improper voltage level has been detected on the fan 2 relay control circuit.
- The voltage conditions are present for at least 30 seconds.
Replace the relay if no shorts or an open on the feed circuit or control circuit is found.
- A faulty connection at the PCM – inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connections.
- Inspect the wiring harness for damage.
- If the harness appears to be okay, disconnect the PCM, turn the ignition ON and observe a DMM connected between the fan 2 relay driver circuit and ground at the PCM harness connector while moving connectors and wiring harnesses related to the fan 2 relay. A change in voltage will indicate the location of the fault.
- With the ignition off, disconnect the relay. Turn ignition ON (DO NOT START). Probe the coil feed circuit of the relay with a test lamp connected to ground.
- Does the test lamp illuminate?
- NO - Check the fuse. If blow check each branch of the circuit for a short and repair. If problem found and repaired, clear DTC.
- YES – A scan tool will be needed to check the command ON and OFF with the control circuit.
- Also test the control circuits of the rely for a short to voltage or an open. If problem found, repair.