• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Ignition 1 Voltage | P0340, P0342, P0458, P0489 | P0403 | -- | -- |
Solenoid Control | P0406, P0489 | P0403 | P0490 | P0404 |
5-Volt Reference | P0106, P0405, P2122, P2138 | P0405 | -- | -- |
EGR Position Sensor Signal | P0405 | P0405 | P0406 | P0404 |
Low Reference | -- | P0406 | -- | -- |
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%¹ |
EGR Position Sensor Signal | 0% | 0% | 99%¹ |
Low Reference | -- | 0% | -- |
¹ 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 |
• | The engine is running. |
• | The DTCs run continuously when the above condition is met. |
The ECM detects an open on the EGR solenoid control circuit.
The ECM detects a short to ground on the EGR solenoid control circuit.
The ECM detects a short to voltage on the EGR solenoid control circuit
DTC P0403, P0489, and P0490 are Type B DTCs.
DTC P0403, P0489, and P0490 are Type B DTCs.
Exhaust Gas Recirculation (EGR) System Description
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
⇒ | 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. |
⇒ | If test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM. |
⇒ | If test lamp does not illuminate, test the control circuit for a short to voltage 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 |