Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC P2080: Exhaust Gas Temperature (EGT) Sensor 1 PerformanceDTC P2080 08: Exhaust Gas Temperature (EGT) Sensor 1 Signal Invalid
DTC P2080 13: Exhaust Gas Temperature (EGT) Sensor 1 Voltage Low/High Temperature
DTC P2080 14: Exhaust Gas Temperature (EGT) Sensor 1 Voltage High/Low Temperature
DTC P2084: Exhaust Gas Temperature (EGT) Sensor 2 Performance
DTC P2084 08: Exhaust Gas Temperature (EGT) Sensor 2 Signal Invalid
DTC P2084 13: Exhaust Gas Temperature (EGT) Sensor 2 Voltage Low/High Temperature
DTC P2084 14: Exhaust Gas Temperature (EGT) Sensor 2 Voltage High/Low Temperature
Circuit/System Description
The diesel exhaust after-treatment system consists of an under hood pre-catalytic converter and an underbody catalytic converter. The underbody catalytic converter also consists of the main Diesel Oxidation Catalyst (DOC) and the coated Diesel Particulate Filter (DPF). One of the main purposes of the DPF is to collect particulates from the engine exhaust in order to minimize discharge of soot to the atmosphere. The soot particles accumulate in the channels of the DPF and are burned off at regular intervals through a process called regeneration. This prevents the DPF from clogging. The ECM commands the DPF regeneration after calculating various vehicle conditions such as DPF pressure difference, exhaust gas temperature, engine oil quality, engine speed, etc. Excessive accumulation of the soot in the DPF can cause a drop in the engine performance. During regeneration, additional fuel is injected via multiple post injections in order to increase the exhaust gas temperature. During this period, the DPF temperature is raised to approximately 600°C and the accumulated soot is oxidized or burned off into carbon dioxide (CO2).
Conditions for Running the DTC
| • | The ignition is ON, or the engine is running. |
| • | The DTCs run continuously when the above conditions are met. |
Conditions for Setting the DTC
P2080, P2080 08, P2084, P2084 08
The ECM detects an invalid signal from the exhaust gas temperature sensor for greater than 1 second.
P2080 13, P2084 13
The ECM detects the exhaust gas temperature sensor is greater than 800°C (1,472°F) for greater than 1 second.
P2080 14, P2084 14
The ECM detects the exhaust gas temperature sensor is less than -55°C (-67°F) for greater than 1 second.
Action Taken When the DTC Sets
DTCs P2080, P2084 are type A DTCs.
Conditions for Clearing the DTC
DTCs P2080, P2084 are type A DTCs.
Diagnostic Aids
| • | If the engine has sat overnight, both EGT sensors and the ECT sensor values should display within 3°C (5°F). |
| • | After starting a cold engine, the EGT sensors temperature should rise steadily, then stabilize. |
| • | High resistance in the circuits of either of the EGT sensors could set a DTC. |
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Ignition On, observe the DTC information with a scan tool. Verify no other DTCs are set.
- Engine running, observe the DTC information with a scan tool. DTCs P2080, P2080 08, P2080 13, P2080 14, P2084, P2084 08, P2084 13, P2084 14 should not set.
- Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
| ⇒ | If any other DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis. |
Circuit/System Testing
- Ignition OFF, and the MAIN fuse removed, disconnect the harness connector at the appropriate EGT sensor.
- Test for less than 5 ohms between the low reference circuit terminal 2 and ground.
- Install the MAIN fuse. Ignition ON, verify the scan tool EGT sensor voltage parameter is greater than 4.9 volts.
- Install a 1A fused jumper wire between the signal circuit terminal 1 and ground. Verify the scan tool EGT sensor parameter is less than 0.5 volts.
- If all circuits test normal, test or replace the EGT sensor.
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
| ⇒ | If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM. |
Important: If the fuse in the jumper wire opens, the signal circuit is shorted to a voltage and the sensor may be damaged.
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for ECM replacement, programming and setup. |
Repair Verification
Ignition ON, observe the scan tool DPF soot mass parameter. The parameter should be less than 5 grams.
| ⇒ | If greater than the specified range, perform a DPF service regeneration. Refer to Exhaust Particulate Filter Cleaning. |
