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 Descriptor
DTC P20E2: Exhaust Temperature Sensor 1-2 CorrelationDiagnostic Fault Information
Circuit | Short to Ground | High Resistance | Open | Short to Voltage |
|---|---|---|---|---|
Exhaust Gas Temperature Sensor 1 Signal | P0545 | P0546 | P20E2 | P0546 |
Exhaust Gas Temperature Sensor 1 Low Reference | -- | P0546 | P20E2 | P0546 |
Exhaust Gas Temperature Sensor 2 Signal | P2032 | P2033 | P20E2 | P2033 |
Exhaust Gas Temperature Sensor 2 Low Reference | -- | P2033 | P20E2 | P2033 |
Circuit/System Description
The exhaust gas temperature (EGT) sensor 1 and 2 are installed to the diesel particulate filter (DPF) housing. The EGT sensor 1 measures the temperature of the exhaust gas in front of oxygen catalyst. The EGT sensor 2 measures the temperature of the exhaust gas in front of filter. The engine control module (ECM) monitors difference of temperature from both sensor inputs continuously. If the ECM detects that both inputs are not within a specified temperature of each other, this DTC will set.
Conditions for Running the DTC
| • | DTCs P0079, P0080, P0117, P0118, P0126, P0182, P0183, P0237, P0238, P0545, P0546, P0642, P0643, P0652, P0653, P2032, P2033, P2454 and P2455 are not set. |
| • | The following conditions are met for longer than 166 minutes: |
| - | The battery voltage is between 10-16 volts. |
| - | The ignition switch is ON. |
| - | The engine speed is between 2,200 RPM. |
| - | The engine speed does not vary more than 25 RPM. |
| - | The fuel quantity is less than 200 mm3/st. |
| - | The fuel quantity does not vary more than 10 mm3/st. |
| - | The fuel rail pressure does not vary more than 1450 psi (10 MPa). |
| - | The fuel temperature is between 8-115°C (46-239°F). |
| - | The engine coolant temperature (ECT) is between 9-106°C (48-228°F). |
| • | The following conditions are met for longer than 7 minutes: |
| - | The DPF status is zero without the regeneration event. |
| - | The intake throttle position is less than 55 percent. |
| - | The VNT control is normal mode. |
| - | The exhaust throttle command is OFF. |
| - | The DPF differential pressure is between -10 and +20 kPa (-1.4 and +2.9 psi). |
Conditions for Setting the DTC
The ECM detects that the difference of the exhaust gas temperature 1 and 2 is more than a predetermined range of the calculated value.
Action Taken When the DTC Sets
DTC P20E2 is a Type B DTC.
Conditions for Clearing the DTC
DTC P20E2 is a Type B DTC.
Diagnostic Aids
| • | A slight to moderate resistance in either signal or low reference circuit can widen the spread between the two EGT sensors and cause this DTC to set. |
| • | An EGT sensor that is skewed lower at various ambient temperatures due to more resistance than is normal can widen the spread between the two sensors and cause this DTC to set. Measure and record the resistance of both EGT sensors 1 and 2 at ambient temperature. Compare those measurements to the Temperature Versus Resistance table. |
Reference Information
Schematic Reference
Connector End View Reference
Engine Control Module Connector End Views
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Circuit/System Verification
Important: Determine the ambient temperature by using an accurate thermometer.
- If the ignition has been OFF for greater than 5 hours, determine which EGT sensor is skewed by comparing EGT Sensor 1 and 2 parameters to the ambient temperature with a scan tool. The readings should be within 19°C (66°F) of each other and also the ambient temperature.
- Ignition ON, observe the scan tool EGT Sensor 1 and 2 parameters. The readings should be between -40 to +999°C (-38 to +1,830°F) depending on the current ambient temperature and the vehicle operating conditions.
- 3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
Important: You must perform Circuit/System Verification before proceeding with Circuit/System Testing.
- Ignition OFF, disconnect both harness connectors at EGT sensor 1 and sensor 2.
- Ignition OFF, test for 4.8 volts between the applicable EGT sensor signal circuit and ground.
- Install a 3A fused jumper wire between the applicable signal circuit and the applicable low reference circuit for EGT sensor. Verify that the DMM is greater than 4.8 volts.
- If all circuits test normal, test or replace the affected sensor.
| ⇒ | If less than 4.8 volts, test the applicable signal circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
| ⇒ | If less than 4.8 volts, test the applicable low reference circuit for 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, setup, and programming |
