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 any Technical Service Bulletins that may apply.
Turn the ignition on.
With the DRB III®, 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) CHECK FOR CURRENT DTC
NOTE: If the PCM detects and stores a DTC, the PCM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the DRB III® at the same time the DTC is displayed.NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.
Turn the ignition on.
With the DRB III®, erase PCM DTCs.
NOTE: It maybe necessary to road test the vehicle for this DTC to set.With the DRB III®, read PCM DTCs.
Did this DTC set again?
Yes
- Go To 3).
No
- Go To 10).
- 3) MEASURE THE VOLTAGE OF THE ENGINE CONTROL RELAY OUPUT CIRCUIT
Turn the ignition off.
Disconnect the MAF/IAT Sensor harness connector.
NOTE: Check connectors - Clean/repair as necessary.Turn the ignition on.
Measure the voltage of the Fused Engine Control Relay Output circuit at the MAF/IAT Sensor harness connector.
Is the voltage above 10 volts?
Yes
- Go To 4).
No
- Repair the Fused Engine Control Relay Ouput circuit for an open.
- Perform POWERTRAIN VERIFICATION TEST - VER 2 .
- 4) IAT SENSOR SIGNAL CIRCUIT SHORT TO VOLTAGE
With the ignition on.
Measure the voltage of the IAT Signal circuit at the MAF/IAT Sensor harness connector.
Is the voltage between 4.7 and 5.2 volts?
Yes
- Go To 5).
No
- 5) CHECK FOR 5-VOLT SUPPLY CIRCUIT SHORT TO IAT SIGNAL CIRCUIT
Turn the ignition off.
Disconnect PCM C3 harness connector.
NOTE: Check connectors - Clean/repair as necessary.Measure the resistance between the IAT Signal circuit and the 5-Volt Supply circuit at the MAF/IAT Sensor harness connector.
Is the resistance above 100 kohms?
Yes
- Go To 6).
No
- Repair the IAT Signal circuit for a short to the 5-Volt Supply circuit.
- Perform POWERTRAIN VERIFICATION TEST - VER 2 .
- 6) SENSOR GROUND CIRCUIT OPEN
With the ignition off.
Measure the resistance of the Sensor Ground circuit from the MAF/IAT Sensor harness connector to the PCM C3 harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go To 7).
No
- Repair the Sensor Ground circuit for an open.
- Perform POWERTRAIN VERIFICATION TEST - VER 2 .
- 7) JUMPER THE IAT SENSOR SIGNAL AND SENSOR GROUND CIRCUITS
With the ignition off.
Reconnect the PCM C3 harness connector.
Connect a jumper wire between the IAT Sensor Signal circuit and the Sensor Ground circuit at the MAF/IAT Sensor harness connector.
Turn the ignition on.
With the DRB III®, read PCM DTCs.
Is DTC P0112 INTAKE AIR TEMPERATURE SENSOR CIRCUIT LOW present?
Yes
- Replace the Mass Air Flow / Intake Air Temperature Sensor. (Refer to FUEL SYSTEM/FUEL INJECTION/MANIFOLD AIR FLOW (MAF) SENSOR - REMOVAL).
- Perform POWERTRAIN VERIFICATION TEST - VER 2 .
No
- Replace and program the Powertrain Control Module. (Refer to ELECTRICAL/ELECTRONIC CONTROL MODULES/POWERTRAIN CONTROL MODULE - REMOVAL) .
- Perform POWERTRAIN VERIFICATION TEST - VER 2 .
- 8) IAT SIGNAL CIRCUIT SHORT TO VOLTAGE
Turn the ignition off.
Disconnect the PCM C3 harness connector.
NOTE: Check connectors - Clean/repair as necessary.Turn the ignition on.
Measure the voltage of the IAT Signal circuit at the MAF/IAT Sensor harness connector.
Is the voltage below 1.0 volt?
Yes
- 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 IAT Signal circuit for a short to voltage.
- Perform POWERTRAIN VERIFICATION TEST - VER 2 .
- 9) IAT SENSOR SIGNAL CIRCUIT OPEN
Turn the ignition off.
Disconnect the PCM C3 harness connector.
NOTE: Check connectors - Clean/repair as necessary.Measure the resistance of the IAT Sensor Signal circuit from the MAF/IAT Sensor harness connector to the PCM C3 harness connector.
Is the resistance below 5.0 ohms?
Yes
- 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 IAT Sensor Signal circuit for an open.
- Perform POWERTRAIN VERIFICATION TEST - VER 2 .
- 10) INTERMITTENT WIRING AND CONNECTORS
The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.
NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs.NOTE: Check for any Technical Service Bulletins that may apply.Using the wiring diagram/schematic as a guide, inspect the wiring and connectors specific to this DTC. Wiggle the wires while checking for shorts and open circuits.
Were any problems found?
Yes
- Repair as necessary.
- Perform POWERTRAIN VERIFICATION TEST - VER 2 .
No
- Test Complete.