• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Ignition 1 Voltage | * | P0403, P0405 | -- | P0404, P042E |
Solenoid Control | P0402 | P0403, P0404 | P0403, P0404 | P0404, P042E |
5-Volt Reference | P0107, P0405, P0452, P0651, P2077, P2106 | P0405 | P0107, P0446, P0453, P0651, P2106 | -- |
EGR Position Sensor Signal | P0405 | P0405 | P0406 | P0404, P042E |
Low Reference | -- | P0406 | -- | -- |
* Engine cranks but does not run and the fuse for the ignition 1 circuit opens. |
Circuit | Short to Ground | Open | Short to Voltage |
---|---|---|---|
Operating Conditions: Engine operating in Closed Loop Parameter Normal Range: 0-4% | |||
Ignition 1 Voltage | -- | -- | -- |
Solenoid Control | 99% | -- | -- |
5-Volt Reference | 0% | 0% | 99%* |
EGR Position Sensor Signal | 0% | 0% | 99%* |
Low Reference | -- | 0% | -- |
* Internal ECM damage may occur if the circuit is shorted to B+. |
Voltage is provided to the exhaust gas recirculation (EGR) valve by the ignition 1 voltage circuit through a fuse. Ground is provided to the EGR valve on the control circuit by a low side driver within the engine control module (ECM). The ECM monitors the voltage on the control circuit of the EGR valve to determine if a failure is present.
The ECM monitors the position of the EGR valve through the EGR valve position sensor. The EGR valve position sensor sends a feedback voltage on the signal circuit to the ECM. The EGR position sensor voltage varies depending on the position of the EGR valve.
The EGR valve utilizes the following circuits:
• | An ignition 1 voltage circuit |
• | A control circuit |
• | A 5-volt reference circuit |
• | A signal circuit |
• | A low reference circuit |
• | DTCs P0112, P0113, P0405, P0406, P0502, P0562, and P0563 are not set. |
• | The engine is running. |
• | The intake air temperature (IAT) is between 3-80°C (37-176°F). |
• | The ignition voltage is between 11-16 volts. |
• | The Desired EGR position is greater than 0 percent and does not change more than 3 percent - DTC P0404 only. |
• | The DTCs run continuously when the above conditions are met. |
• | The engine is running. |
• | The ignition voltage is between 11-16 volts. |
• | The DTC runs continuously when the above conditions are met. |
The ECM detects an open, short to ground or voltage on the control circuit of the EGR valve.
The ECM detects a difference between the actual EGR position and the commanded EGR position of more than 15 percent.
The ECM detects that the EGR position sensor percentage is less than 2 percent.
The ECM detects that the EGR position sensor percentage is greater than 98 percent.
The ECM detects the difference between the actual EGR position and the learned EGR position is greater than 10 percent.
• | DTCs P0403, P0405, and P0406 are Type A DTCs. |
• | DTCs P0404 and P042E are Type B DTCs. |
• | DTCs P0403, P0405, and P0406 are Type A DTCs. |
• | DTCs P0404 and P042E are Type B DTCs. |
• | If a shared 5-volt reference circuit is shorted to ground or shorted to a voltage, other 5-volt reference circuits may be affected. |
• | The scan tool 5 volt reference parameter should display between 4.8-5.2 volts. |
Exhaust Gas Recirculation (EGR) System Description
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
⇒ | If P0651 is set, refer to DTC P0641 or P0651. |
Important: The scan tool EGR Position Sensor parameter will display less than 100 percent when the EGR is commanded to 100 percent.
⇒ | If the test lamp does not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition 1 voltage circuit fuse is open, test all components connected to the ignition 1 voltage circuit and replace as necessary. |
Important: The scan tool EGR Position Sensor parameter will display less than 100 percent when the EGR is commanded to 100 percent.
⇒ | If test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM. |
⇒ | If test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | 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 5-volt reference circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If not within the specified range, replace the EGR valve. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for ECM replacement, setup, and programming |