P0070-AMBIENT AIR TEMPERATURE SIGNAL VOLTAGE TOO HIGH
For a complete wiring diagram Refer to Section 8W
- When Monitored:
With the ignition on.
- Set Condition:
The Ambient Air Temperature Sensor signal is above 4.82 volts for 0.5 second.
| Possible Causes |
| AMBIENT AIR TEMP SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE |
| AMBIENT AIR TEMP SENSOR GROUND CIRCUIT OPEN |
| AMBIENT AIR TEMP SENSOR SIGNAL CIRCUIT OPEN |
| AMBIENT TEMPERATURE SENSOR |
| ENGINE CONTROL MODULE |
Diagnostic Test
1. CHECK FOR ACTIVE DTCNOTE: If the ECM detects and stores a DTC, the ECM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the scan tool 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 scan tool, erase ECM DTCs.
Turn the ignition off for 10 seconds.
Turn the ignition on.
Monitor the scan tool for ECM DTCs.
Did this DTC set again?
Yes
- Go To2
No
- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
2. AMBIENT AIR TEMP SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Disconnect the Ambient Air Temperature Sensor harness connector.
Disconnect the ECM harness connectors.
Remove the ASD Relay from the PDC.
Connect a jumper wire between cavity 30 and cavity 87 of the ASD Relay connector.
Turn the ignition on.
Measure the voltage on the Ambient Air Temperature Sensor Signal circuit.
NOTE: Remove the jumper wire.
Is the voltage below 1.0 volt?
Yes
- Go To3
No
- Repair the Ambient Air Temperature Sensor Signal circuit for a short to voltage.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
3. AMBIENT AIR TEMP SENSOR SIGNAL CIRCUIT OPEN
Turn the ignition off.
Measure the resistance of the Ambient Air Temperature Sensor Signal circuit.
Is the resistance below 10.0 ohms?
Yes
- Go To4
No
- Repair the Ambient Air Temperature Sensor Signal circuit for an open.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
4. AMBIENT TEMPERATURE SENSOR
Connect the ECM harness connectors.
Connect a jumper wire between the Ambient Temperature Sensor Signal and Sensor Ground circuits in the Ambient Temperature Sensor harness connector.
Turn the ignition on.
Monitor the scan tool for ECM DTCs.
Does the scan tool display P0070 AMB TEMP. SENSOR CIRCUIT SIGNAL VOLTAGE TOO LOW?
Yes
- Replace the Ambient Temperature Sensor.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
No
- Go To5
5. AMBIENT TEMP SENSOR GROUND CIRCUIT OPEN
Turn the ignition off.
Disconnect the ECM harness connectors.
Measure the resistance of the Sensor Ground circuit between the ECM harness connector and the Ambient Temperature Sensor harness connector.
Is the resistance below 10.0 ohms?
Yes
- Replace and program the Engine Control Module in accordance with the Service Information.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
No
- Repair the Ambient Air Temperature Sensor Ground circuit for an open.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).