Diagnostic Instructions
DTC Descriptor
DTC P040B: Exhaust Gas Recirculation (EGR) Temperature Sensor 1 Performance
Diagnostic Fault Information
Circuit
| Short to Ground
| Open
| Short to Voltage
|
EGR Temperature Sensor 1 or EGR Temperature Sensor 2
| P040C or P041C
| P040D or P041D
| --
|
Circuit/System Description
The engine control module (ECM) supplies 5 volts to the EGR cooler exhaust gas temperature sensor on the 5-volt reference circuit. The ECM also provides a ground on the low reference circuit. The EGR cooler exhaust gas temperature sensor
provides a signal to the ECM on the EGR cooler 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 EGR cooler exhaust gas temperature, such as low engine load. The
ECM should detect high signal voltage at a high EGR cooler exhaust gas temperature, such as high engine load. The ECM monitors the EGR cooler exhaust gas temperature sensor signal for voltage outside the normal range of the EGR cooler exhaust gas temperature
sensor.
Conditions for Running the DTC
| • | DTCs P0182, P0183, P0237, P0238, P0409, P040C, P040D, P0506, P0507, P0642, P0643, P0652, P0653, P2228 and P2229 are not set. |
| • | The following conditions are met for 200 seconds: |
| - | The battery voltage is between 10-16 volts. |
| - | The ignition is ON for longer than 2 seconds. |
| - | The actual EGR position is more than 20 percent. |
| - | The engine speed is more than 1000 RPM. |
| - | The fuel temperature is less than 115°C (239°F). |
| • | The following conditions are met for 10 seconds: |
| - | The intake throttle position is less than 55 percent. |
| - | The exhaust brake control is commanded OFF. |
| - | The DPF status is Not during regeneration. |
| - | The differential pressure is between -10 and +20 kPa. |
Conditions for Setting the DTC
The ECM detects EGR gas temperature error for longer than 10 seconds.
Action Taken When the DTC Sets
DTC P040B is a Type B DTC.
Conditions for Clearing the DTC
DTC P040B is a Type B DTC.
Diagnostic Aids
Inspect for any recent engine mechanical repairs. An incorrectly installed EGR sensor will cause this DTC to set.
Reference Information
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Component Connector End Views
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 EGR sensor by inspecting for the following conditions:
| • | Loose or improper installation |
Circuit/System Testing
Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
- Ignition OFF, disconnect the harness connector at the EGR gas temperature sensor.
- Ignition OFF, test for less than 5 ohms between the low reference circuit terminal A and ground.
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the control module. |
- Ignition ON, verify the scan tool EGR gas temperature parameter is more than 950°C (1742°F).
| ⇒ | If greater than the specified range, test the signal circuit terminal B for a short to ground. If the circuit tests normal, replace the control module. |
- Install a 3-amp fused jumper wire between the signal circuit terminal A and the low reference circuit terminal B. Verify the scan tool EGR gas temperature parameter is less than 0°C (32°F) .
| ⇒ | If voltage is less than the specified range, test the valve position drive circuits circuit for high resistance. If the circuit tests normal, replace the ECM. |
| ⇒ | If less 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 control module. |
| ⇒ | If all circuits test normal, replace the EGR gas temperature sensor. |
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
