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 provide an overview of each diagnostic category. |
DTC Descriptors
DTC P0545: Exhaust Gas Temperature (EGT) Sensor 1 Circuit Low VoltageDTC P0546: Exhaust Gas Temperature (EGT) Sensor 1 Circuit High Voltage
Diagnostic Fault Information
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
EGT Sensor 1 Signal | P0545 | P0546 | P0546 |
Exhaust Gas Temperature Sensor 1 Low Reference | -- | P0546 | P0546 |
Typical Scan Tool Data
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Operating Conditions: Ignition ON Parameter Normal Range: 0-1 000°C (32-1,832°F) | |||
Exhaust Gas Temperature Sensor 1 Signal | 950°C (1,742°F) | 0°C (32°F) | 0°C (32°F) |
Exhaust Gas Temperature Sensor 1 Low Reference | -- | -- | -- |
Circuit/System Description
The engine control module (ECM) supplies 5 volts to the DOC exhaust gas temperature sensor on the 5-volt reference circuit. The ECM also provides a ground on the low reference circuit. The DOC exhaust gas temperature sensor provides a signal to the ECM on the DOC exhaust gas temperature signal circuit which is relative to the pressure changes in the manifold. The ECM should detect a low signal voltage at a DOC exhaust gas temperature, such as low engine load. The ECM should detect high signal voltage at a high DOC exhaust gas temperature, such as high engine load. The ECM monitors the DOC exhaust gas temperature sensor signal for voltage outside the normal range of the DOC exhaust gas temperature sensor.
Conditions for Running the DTC
P0545
| • | DTC P0546 is not set. |
| • | The battery voltage is between 10-16 volts. |
| • | The ignition is ON for longer than 2 seconds. |
P0546
| • | DTCs P0112, P0113, and P0545 are not set. |
| • | The battery voltage is between 10-16 volts. |
| • | The ignition switch is ON for longer than 2 seconds. |
| • | The engine speed is more than 1,000 RPM. |
| • | The engine run time is more than 300 seconds. |
Conditions for Setting the DTC
P0545
The ECM detects that the DOC exhaust gas temperature sensor 1 signal voltage is less than 0.18 volt.
P0546
The ECM detects that the DOC exhaust gas temperature sensor 1 signal voltage is more than 4.9 volts.
Action Taken When the DTC Sets
DTCs P0545 and P0546 are Type A DTCs.
Conditions for Clearing the DTC
DTCs P0545 and P0546 are Type A DTCs.
Diagnostic Aids
Inspect for any recent engine mechanical repairs. An incorrectly installed EGT sensor 1 will cause this DTC to set.
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
Verify the integrity of the EGT sensor by inspecting for the following conditions:
| • | Damaged components |
| • | Loose or improper installation |
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the exhaust gas temperature 1 sensor.
- Ignition ON, verify the scan tool Exhaust Gas Temperature 1 parameter is less than 1°C (34°F).
- Install a 3-amp fused jumper wire between the signal circuit terminal A and the low reference circuit terminal B. Verify the scan tool Exhaust Gas Temperature 1 parameter is more than 950°C (1,742°F).
- If all circuits test normal, replace the exhaust gas temperature 1 sensor.
Important: Perform the Circuit/System Verification before proceeding with the Circuit/System Testing.
| ⇒ | If greater than the specified range, test the signal circuit terminal B for a short to ground. If the circuit tests normal, replace the ECM. |
| ⇒ | If less than the specified range, test the signal circuit and low reference 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, setup, and programming |
