P00DB

P00DB-AMBIENT AIR TEMPERATURE SENSOR CIRCUIT LOW




For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation

The Diesel Exhaust Fluid (DEF) Ambient Air Temperature Sensor is mounted to the DEF Supply Pump Assembly bracket. The Powertrain Control Module provides a 5-Volt Signal and a sensor ground circuit for the DEF Ambient Air Temperature Sensor. The DEF Ambient Air Temperature Sensor signal is provided to the DEF Dosing Control Unit via the PCM. The DEF Dosing Control Unit uses this information along with the diesel exhaust fluid temperature information to determine if the Selective Catalytic Reduction (SCR) system is required.

- When Monitored:
With the ignition on.

- Set Condition:
The Powertrain Control Module detects that the DEF Ambient Air Temperature Sensor signal voltage is below 0.12 of a volt for one second.





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

1. ACTIVE DTC

NOTE: If there are any 5-Volt supply DTCs present, repair those DTCs before proceeding with this test.

1. Turn the ignition on.
2. With the scan tool, record all Freeze frame data.
3. With the scan tool, erase DTCs.
4. Turn the ignition off for 75 seconds.
5. Turn the ignition on.
6. With the scan tool, read DTCs.

Did the DTC return?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION - 6.7L diagnostic procedure. Intermittent Condition Test

2. CHECK THE DEF AMBIENT AIR TEMPERATURE SENSOR
1. With the scan tool, Erase DTCs.
2. Turn the ignition off.
3. Disconnect the DEF Ambient Air Temperature Sensor harness connector.
4. Turn the ignition on.
5. With the scan tool, View DTCs.

Did the DTC P00DC-DEF AMBIENT AIR TEMPERATURE SENSOR HIGH set as active?

Yes

- Replace the DEF Ambient Air Temperature Sensor. Diesel Exhaust Fluid Ambient Temperature Sensor - Removal.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 3

3. CHECK THE (G32) DEF AMBIENT AIR TEMPERATURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND




1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.

NOTE: Check connectors - Clean/repair as necessary.

3. Measure the resistance between ground and the (G32) DEF Ambient Air Temperature Sensor Signal circuit at the DEF Ambient Air Temperature Sensor harness connector.

Is the resistance above 10k Ohms?

Yes

- Go To 4

No

- Repair the (G32) DEF Ambient Air Temperature Sensor Signal circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

4. CHECK FOR THE (G32) DEF AMBIENT AIR TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO ANOTHER CIRCUIT
1. Measure the resistance between the (G32) DEF Ambient Air Temperature Sensor Signal circuit and the all other circuits at the PCM C2 harness connector.

Is the resistance above 10k Ohms?

Yes

- Replace the Powertrain Control Module. Powertrain Control Module - Removal
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Repair the short between the (G32) DEF Ambient Air Temperature Sensor Signal circuit and the circuit that measured below 10k Ohms.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.