P2084

P2084-EXHAUST GAS TEMP SENSOR CIRCUIT PERFORMANCE - BANK 1 SENSOR 2







Theory of Operation

The Exhaust Temperature Sensors are used by the Engine Control Module (ECM) to monitor the engine exhaust temperatures in the after treatment system. The Exhaust 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 voltage on the signal pin and converts this to a temperature value. This fault is set by the ECM if it detects that the After treatment Diesel Particulate Filter inlet temperature sensor reading is not increasing with engine operating temperature after engine startup. The ECM will illuminate the MIL lamp after the diagnostic runs and fails on two consecutive drive cycles. The ECM will turn off the MIL lamp after the diagnostic runs and passes on four consecutive drive cycles. The ECM will disable active regeneration mode.

- When Monitored:
Engine Running.

- Set Condition:
The ECM detects that the after treatment diesel particulate filter inlet temperature sensor reading is not increasing with engine operating temperature after engine startup.





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

1. OTHER DTCS
1. With a scan tool read DTCs.

Do you have any other DTC for the Exhaust Temperature Sensors?

Yes

- Repair all other DTCs first.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test

No

- Go To 2

2. EXHAUST TEMPERATURE
1. With the scan tool, read the Exhaust Temperature Sensors to determine the exhaust temperature.

Is the temperature reading above 225°F?

Yes

- Go To 3

No

- Go To 4

3. EXHAUST TEMPERATURE SENSOR 1/2 AND 1/3
1. Start the engine.
2. Raise the engine speed to 2500 RPM's for two minutes.

Do the temperature readings of Exhaust Temperature Sensor 1/2 and Exhaust Temperature Sensor 1/3 change in value at least 5°F?

Yes

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

No

- Replace the Exhaust Temperature Sensor that did not change in value by at least 5°F or is not updating.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

4. EXHAUST TEMPERATURE SENSOR 1/2 AND 1/3
1. Start the engine and allow it to idle for 10 minutes.
2. With the scan tool, read the values of Exhaust Temperature Sensor 1/2 and Exhaust Temperature Sensor 1/3.

Do both temperature sensors read above 150°F and are the values of both temperature sensors updating?

Yes

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test

No

- Replace the Exhaust Temperature Sensor that is not above 150°F or is not updating on the scan tool.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.