Diagnostic Test
- 1)
PRE-DIAGNOSTIC CHECK OUT
NOTE: Always perform diagnostics with a fully charged battery.NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs.NOTE: Check for applicable TSBs related to the problem.
Turn the ignition on.
With the DRB III(R), read PCM DTCs.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors. Repair as necessary.
Perform this procedure prior to symptom diagnosis.
Continue
- Go To 2).
- 2)
O2 HEATER ELEMENT
NOTE: Check the Engine Control Fuse 2 in the Relay Control Module. If it is open, multiple DTCs will be set in the PCM. Determine the cause of the open fuse before continuing using the wiring diagrams/schematics as a guide.NOTE: Allow the O2 Sensor to cool down to room temperature.
Turn the ignition off.
Disconnect the O2 Sensor harness connector.
NOTE: Check connectors - Clean/repair as necessary.Measure the resistance of the O2 Sensor Heater element at the O2 Sensor harness connector.
Is the O2 Sensor Heater element resistance between 8.5 and 9.5 ohms?
Yes
- Go To 3).
No
- Replace the Oxygen Sensor. (Refer to FUEL SYSTEM/FUEL INJECTION/O2 SENSOR - REMOVAL) .
- Perform POWERTRAIN VERIFICATION TEST - VER 2 .
- 3)
O2 HEATER CONTROL CIRCUIT SHORT TO GROUND
With the ignition off.
Disconnect the PCM harness connectors.
NOTE: Check connectors - Clean/repair as necessary.Measure the resistance between ground and the O2 Heater Control circuit.
Is the resistance above 100 kohms?
Yes
- Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary. Replace and program the Powertrain Control Module.(Refer to ELECTRICAL/ELECTRONIC CONTROL MODULES/POWERTRAIN CONTROL MODULE - REMOVAL) .
- Perform POWERTRAIN VERIFICATION TEST - VER 2 .
No
- Repair the O2 Heater Control circuit for a short to ground.
- Perform POWERTRAIN VERIFICATION TEST - VER 2 .