P0546

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





For a complete wiring diagram refer to the Wiring Information Electrical Diagrams.

Theory of Operation

The aftertreatment temperature sensors are used by the Electronic Control Module (ECM) to monitor the engine exhaust temperatures in the aftertreatment system. The aftertreatment temperature sensors are thermistors and change resistance based on the temperature being measured. The ECM provides a 5 volt reference voltage to the sensor. The ECM 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 ECM signal voltage only pulls down a small amount through the sensor to ground.Therefore, the ECM 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 ECM senses a low signal voltage, or a high temperature. The ECM 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 ECM illuminates the MIL lamp immediately when the diagnostic runs and fails. A default value for the aftertreatment diesel oxidation catalyst inlet temperature reading will be used and active regeneration of the diesel particulate filter will be disabled. The ECM 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 Signal voltage goes above 4.9 volts for six minutes.





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 30 seconds.
5. Turn the ignition on.
6. With the scan tool, read DTCs.

Did the DTC reset?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION - DIESEL (Diagnostic Procedure). Intermittent Condition Test

2. (K185) EXHAUST GAS TEMPERATURE 1 SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE




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

NOTE: Check connectors - Clean/repair as necessary.

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

Is the voltage higher than 5.1 volts?

Yes

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

No

- Go To 3
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test

3. TEMPERATURE SENSOR




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

Does DTC P0545 become active?

Yes

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

No

- Go To 4

4. (K185) EXHAUST GAS TEMPERATURE SENSOR 1 SIGNAL CIRCUIT OPEN




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

Is the resistance below 10.0 ohms?

Yes

- Go To 5

No

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

5. (K900) SENSOR GROUND CIRCUIT OPEN




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

Is the resistance below 10.0 ohms?

Yes

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

No

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