P1115

P1115-GENERAL TEMPERATURE RATIONALITY







- When Monitored:
Ignition on and battery voltage greater than 10 volts.

- Set Condition:
Ambient Air, Engine Coolant, and Intake Air Temp sensor inputs are compared under cold start conditions. After start up the temp readings are monitored. If two of the three readings agree and the third doesn't, a DTC is stored. Two Trip Fault. Three good trips to turn off the MIL.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DTC
1. Ignition on, engine not running.
2. With a scan tool, read the DTCs.

NOTE: All ECT, Intake Air, and Ambient Air Temperature Sensor codes must be diagnosed and repaired before continuing.

NOTE: In cold weather, this DTC could be set by a non-OEM approved block heater and no repair would be required.

Is the DTC active at this time?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition Test
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

2. TEMPERATURE SENSOR CIRCUIT
1. With a scan tool, read the ECT, Ambient Air Temp, and Intake Air Temp Sensor temp values.
2. Start the engine.
3. Allow the engine to reach normal operating temperature while monitoring the three Sensor temperature values.

Is the temperature for each of the Sensors increasing properly?

Yes

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition Test
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 3

3. TEMPERATURE SENSOR
1. Ignition on, engine not running.
2. Disconnect the suspected faulty sensor.
3. Connect a jumper wire between the (ECT/IAT) Sensor Signal circuit and the (K900) Sensor ground circuit.
4. Connect a jumper wire between the AAT sensor Signal circuit and the (G931) AAT Return circuit.
5. With the scan tool, read the voltage of the suspected Sensor.

NOTE: Remove the jumper wire before continuing.

Did the voltage reading start at 4.8 to 5.0 volts and decrease to 0 volts when the jumper wire was installed?

Yes

- Replace the faulty Sensor.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 4

4. EXCESSIVE RESISTANCE IN THE TEMPERATURE SENSOR SIGNAL CIRCUIT
1. Turn the ignition off.
2. Disconnect the PCM harness connectors (ECT/IAT).
3. Disconnect the TIPM harness connectors (AAT).

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 PCM Pinout Box 8815 to perform diagnosis.

4. Measure the resistance of the (ECT/IAT) Sensor Signal circuit from the Sensor harness connector to the appropriate terminal of special tool #8815.
5. Measure the resistance of the (G31) AAT Signal circuit from the AAT sensor harness connector to the TIPM harness connector.

Is the resistance above 5.0 ohms.

Yes

- Repair the excessive resistance in the Temperature Sensor Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 5

5. EXCESSIVE RESISTANCE IN THE (K900) SENSOR GROUND CIRCUIT/G931 AAT RETURN
1. Measure the resistance of the (K900) Sensor ground circuit from the Sensor harness connector to the appropriate terminal of special tool #8815.
2. Measure the resistance of the (G931) AAT Return circuit from the AAT sensor harness connector to the TIPM harness connector.

Is the resistance above 5.0 ohms.

Yes

- Repair the excessive resistance in the (K900) Sensor ground circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 6

6. PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

1. Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

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