Diagnostic Test
WARNING: This page is about a different variant/trim than selected.
- CHECK FOR AN ACTIVE DTC
- Turn the ignition on.
- With the scan tool, read DTCs.
Is the DTC active?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
- CHECK THE (F944) FUSED RUN/START CIRCUIT
- Turn the ignition off.
- Remove the Vacuum Pump Relay from the relay connector in the PDC.
- Turn the ignition on.
- Using a 12-volt test light connected to ground, probe the (F944) Fused RUN/START circuit (terminal 85) at the Vacuum Pump Relay connector.
Does the test light illuminate brightly?
Yes
- Go To 3
No
- Repair the (F944) Fused RUN/START circuit for an open.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- VACUUM PUMP RELAY
- Measure the resistance of the Vacuum Pump Relay Coil.NOTE:
Measure across terminals 85 and 86 of the relay.
Is the resistance between 60 to 80 Ohms?
Yes
- Go To 4
No
- Verify that there is good pin to terminal contact in the Vacuum Pump Relay and Powertrain Control Module connectors. If OK, replace the Vacuum Pump Relay.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Measure the resistance of the Vacuum Pump Relay Coil.
- CHECK THE (T110) VACUUM PUMP RELAY CONTROL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
- Disconnect the PCM C1 harness connector.CAUTION:
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.
- Connect the (special tool #10436, Adapter, GPEC Diagnostic).
- Measure the resistance of the (T110) Vacuum Pump Relay Control circuit (terminal 86) from the Vacuum Pump Relay connector to the GPEC Adaptor.
Is the resistance below 3.0 Ohms?
Yes
- Go To 5
No
- Repair the (T110) Vacuum Pump Relay Control circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Disconnect the PCM C1 harness connector.
- CHECK THE (T110) VACUUM PUMP RELAY CONTROL CIRCUIT FOR A SHORT TO GROUND
- Measure the resistance between ground and the (T110) Vacuum Pump Relay Control circuit (terminal 86) at the Vacuum Pump Relay connector.
Is the resistance above 10k Ohms?
Yes
- Go To 6
No
- Repair the (T110) Vacuum Pump Relay Control circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Measure the resistance between ground and the (T110) Vacuum Pump Relay Control circuit (terminal 86) at the Vacuum Pump Relay connector.
- POWERTRAIN CONTROL MODULE (PCM)
- Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Electric Vacuum Pump, PDC and the Powertrain Control Module (PCM).
- Look for any chafed, pierced, pinched or partially broken wires.
- Look for broken, bent, pushed out or corroded terminals.
- Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
- Look for the data to change or for the DTC to reset during the wiggle test.
- Perform any Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Replace the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .