Chrysler PT Cruiser 2001 Service Manual Supplement page 2575

Symptom:
P0401 - EGR SYSTEM FAILURE
When Monitored and Set Condition:
P0401 - EGR SYSTEM FAILURE
When Monitored: With engine temp greater than 82 degress C (180 degress F) ambient
temp above 32 degress C (89 degress F), engine in closed loop, O2 sensor operational,
engine under a steady load with the throttle open, and 02 controller not at or near its
limits.
Set Condition: Conditions are met, the EGR is turned off and on momentarily. The
oxygen sensor signal is monitor for changes in its output signal during this test. If no
significant change or too much change is seen, a flag is set.
EGR SOLENOID
EGR VALVE OPEN AT IDLE
WIRING HARNESS INTERMITTENT
ASD RELAY OUTPUT CIRCUIT OPEN
EGR SOLENOID CONTROL CKT OPEN
EGR SOLENOID CONTROL CKT SHORT TO GND
EGR SOLENOID CONTROL CKT SHORTED TO VOLTAGE
PCM OPEN INTERNALLY
PCM SHORTED INTERNALLY
TEST
1 Note: Inspect all vacuum hoses related to the EGR system before continu-
ing.
Start the engine and allow the engine to reach operating temperature.
Allow the engine to idle.
Does the engine idle smoothly?
Yes → Go To 2
→ Go To 9
No
2 Turn the ignition on.
Turn all accessories off.
Start the engine. Allow the engine to reach normal operating temperature.
With the DRB, enter Engine System Test, then EGR System Test.
Actuate the FLOW function in the EGR System Test.
Did the engine run rough or stall?
Yes → Go To 3
→ Go To 4
No
POSSIBLE CAUSES
ACTION
115
DRIVEABILITY - GAS
APPLICABILITY
All
All