P0546

P0546-EXHAUST GAS TEMPERATURE SENSOR CIRCUIT HIGH - BANK 1 SENSOR 1





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

Theory of Operation

The after treatment temperature sensors are used by the Powertrain Control Module (PCM) to monitor the engine exhaust temperatures in the after treatment system. The after treatment temperature sensors are thermistors and change resistance based on the temperature being measured. The PCM provides a 5-Volt reference voltage to the sensor. The PCM monitors the change in signal voltage and converts this to a temperature value. When the exhaust gas temperature is cold, the sensor or thermistor resistance is high. The PCM signal voltage only pulls down a small amount through the sensor to ground.Therefore, the PCM senses a high signal voltage or low temperature. When the exhaust gas temperature is hot, the sensor resistance is low. The signal voltage pulls down a large amount. Therefore, the PCM senses a low signal voltage, or a high temperature. The PCM will set the fault if it detects that the diesel oxidation catalyst inlet exhaust gas temperature sensor signal voltage is greater than a calibrated voltage (VDC) for more than a calibrated time. The PCM illuminates the MIL lamp immediately when the diagnostic runs and fails. A default value for the after treatment diesel oxidation catalyst inlet temperature reading will be used and active regeneration of the diesel particulate filter will be disabled. The PCM will turn off the MIL lamp immediately after the diagnostic runs and passes.

- When Monitored:
Ignition on.

- Set Condition:
The Exhaust Gas Temperature Sensor 1/1 Signal voltage goes above 4.9 Volts for 15.0 seconds.





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

1. ACTIVE DTC
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 reset?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test

2. CHECK THE (K185) EXHAUST GAS TEMPERATURE 1/1 SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE




1. Ignition on.
2. Disconnect the Exhaust Gas Temperature Sensor 1/1 harness connector.

NOTE: Check connectors - Clean/repair as necessary.

3. Measure the voltage on the (K185) Exhaust Gas Temperature Sensor 1/1 Signal circuit at the Exhaust Gas Temperature Sensor 1/1 harness connector.

Is the voltage above 5.1 Volts?

Yes

- Repair the (K185) Exhaust Gas Temperature Sensor 1/1 Signal circuit for a short to voltage.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 3

3. CHECK THE (K185) EXHAUST GAS TEMPERATURE SENSOR 1/1 SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE




1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
3. Measure the resistance of the (K185) Exhaust Gas Temperature Sensor 1/1 Signal circuit between the Exhaust Gas Temperature Sensor 1/1 harness connector and the PCM C2 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 4

No

- Repair the (K185) Exhaust Gas Temperature Sensor 1/1 Signal circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

4. CHECK THE (K900) SENSOR GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE




1. Measure the resistance of the (K900) Sensor ground circuit between the Exhaust Gas Temperature Sensor 1 harness connector and the PCM C2 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 5

No

- Repair the (K900) Sensor ground circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

5. CHECK THE TEMPERATURE SENSOR




1. While monitoring the scan tool, connect a jumper between the Exhaust Temperature Sensor 1/1 Signal circuit and (K900) Sensor Ground circuit at the Exhaust Temperature Sensor 1/1 harness connector.

Does DTC P0545 become active?

Yes

- Replace the Exhaust Gas Temperature Sensor 1/1.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

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