P0400

(P0400) EGR SYSTEM PERFORMANCE






When Monitored and Set Condition
^ When Monitored: A constant engine speed between 900 and 1700 RPM and no other EGR or MAP sensor faults.
^ Set Condition: The PCM commands the EGR valve to open. The MAP sensor value must drop by a minimum of 54 mbar (1.6 in Hg) when EGR is commanded open or a fault is set.

POSSIBLE CAUSES
EGR SOLENOID CONTROL CIRCUIT OPEN
EGR SOLENOID CONTROL CIRCUIT SHORT TO GROUND
EGR SOLENOID CONTROL CIRCUIT SHORT TO VOLTAGE
FUSED ENGINE CONTROL RELAY OUTPUT CIRCUIT OPEN
EGR SOLENOID
EGR VALVE
POWERTRAIN CONTROL MODULE

Diagnostic Test
1. EGR OPERATION
Turn the ignition on.
Turn all accessories off.
Start the engine.
Allow the engine to reach normal operating temperature.
Does the engine run rough or stall?
Yes>> Go To 2
No>> Go To 3

2. EGR VALVE OPEN AT IDLE
Turn the ignition off. Disconnect the EGR Solenoid harness connector.

Note: Check connectors-Clean/repair as necessary. Start engine. Attempt to allow the engine to idle.

Does the engine run rough or stall?
Yes>> Inspect the EGR tube assembly. If OK, replace the EGR valve.
Perform Powertrain Verification Test - Ver 2
No>> Go To 3

3. EGR SOLENOID





Turn the ignition off. Disconnect the EGR solenoid harness connector.

Note: Check connectors-Clean/repair as necessary.

Connect a 12-volt test lamp between the EGR Solenoid Control circuit and the EGR Solenoid Fused Engine Control Relay Output circuit.
Turn the ignition on.
With the DRB III, actuate the EGR solenoid.
Does the test flash on and off?
Yes>> Replace the EGR Solenoid.
Perform Powertrain Verification Test - Ver 2
No>> Go To 4

4. FUSED ENGINE CONTROL RELAY OUTPUT CIRCUIT OPEN





With the ignition on.
Measure the voltage of the Fused Engine Control Relay Output circuit at the EGR Solenoid harness connector.
Is the voltage above 10 volts?
Yes>> Go To 6
No>> Repair the Engine Control Relay Output circuit for an open.
Perform Powertrain Verification Test - Ver 2

5. EGR SOLENOID CONTROL CIRCUIT SHORT TO GROUND





Turn the ignition off.
Disconnect PCM C2 harness connector.

Note: Check connectors-Clean/repair as necessary. Measure the resistance between ground and the EGR solenoid control circuit.

Is resistance below 100 ohms?
Yes>> Repair the EGR solenoid control circuit for a short to ground.
Perform Powertrain Verification Test - Ver 2
No>> Go To 6

6. EGR SOLENOID CONTROL CIRCUIT OPEN





With the ignition off.
Measure the resistance of the EGR Solenoid Control circuit from the EGR
Solenoid harness connector to the PCM C2 harness connector.
Is the resistance below 5.0 ohms?
Yes>> Go To 7
No>> Repair the EGR Solenoid Control circuit for an open.
Perform Powertrain Verification Test - Ver 2

7. EGR SOLENOID CONTROL CIRCUIT SHORTED TO VOLTAGE





Turn the ignition on.
Measure the voltage of the EGR Solenoid Control circuit at the EGR Solenoid connector.
Is the voltage above 1.0 volt?
Yes>> Repair the EGR Solenoid Control circuit short to voltage.
Perform Powertrain Verification Test - Ver 2
No>> Replace and program the Powertrain Control Module.
Perform Powertrain Verification Test - Ver 2