P0113
P0113-INTAKE AIR TEMPERATURE SENSOR CIRCUIT HIGHP0113-Intake Air Temperature Sensor Circuit High:
Theory of Operation
Intake Air Temperature Sensor performance looks at the outputs of three temperature sensors and compare them under cold start conditions. Following a start to run delay time, the outputs of the ambient, engine coolant, and intake air temperature sensors will be compared. If the engine coolant and ambient air temperature sensors agree and the intake air temperature does not agree, the intake air temperature sensor is declared as irrational.
WHEN MONITORED
With the ignition on. Battery voltage greater than 10.4 volts.
SET CONDITION
The Intake Air Temperature (IAT) sensor circuit voltage at the PCM goes above 4.98 volts for 2.8 seconds. One Trip Fault. Three good trips to turn off the MIL.
POSSIBLE CAUSES
- (K21) IAT signal circuit shorted to battery voltage
- (K21) IAT signal circuit open
- (K900) Sensor ground circuit open
- IAT sensor
- PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
Diagnostic Test
1. IAT SENSOR VOLTAGE ABOVE 4.98 VOLTS
Ignition on, engine not running.
With a scan tool, read the Intake Air Temperature Sensor voltage.
Q: Is the voltage above 4.98 volts?
YES: Go To 2
NO: Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Component Tests and General Diagnostics
Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
2. IAT SENSOR
Turn the ignition off.
Disconnect the Intake Air Temperature Sensor harness connector.
Connect a jumper wire between the (K21) IAT Signal circuit and the (K900) Sensor ground circuit in the IAT Sensor harness connector.
Ignition on, engine not running.
With a scan tool, read the IAT Sensor voltage.
Q: Is the voltage below 1.0 volt with the jumper wire installed?
YES: Replace the IAT Sensor. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 3
NOTE: Remove the jumper wire before continuing.
3. (K21) IAT SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
Disconnect the C2 PCM harness connector.
Ignition on, engine not running.
Measure the voltage on the (K21) IAT Signal circuit in the IAT Sensor harness connector.
Q: Is the voltage above 0 volts?
YES: Repair the short to battery voltage in the (K21) IAT Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 4
4. (K21) IAT SIGNAL CIRCUIT OPEN
Turn the ignition off.
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 Miller Special Tool #8815 to perform diagnosis.
Measure the resistance of the (K21) IAT Signal circuit from the IAT Sensor harness connector to the appropriate terminal of special tool #8815.
Q: Is the resistance below 5.0 ohms?
YES: Go To 5
NO: Repair the open in the (K21) IAT Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
5. (K900) SENSOR GROUND CIRCUIT OPEN
Measure the resistance of the (K900) Sensor ground circuit from the IAT Sensor harness connector to the appropriate terminal of special tool #8815.
Q: Is the resistance below 5.0 ohms?
YES: Go To 6
NO: Repair the open in the (K900) Sensor ground circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
6. PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.
Q: Were there any problems found?
YES: Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Replace and program the Powertrain Control Module. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test