Chrysler PT Cruiser 2001 Service Manual Supplement page 2517

Symptom:
P0118-ECT SENSOR VOLTAGE TOO HIGH
When Monitored and Set Condition:
P0118-ECT SENSOR VOLTAGE TOO HIGH
When Monitored: With the ignition on and battery voltage greater than 10.4 volts.
Set Condition: The engine coolant temperature (ECT) sensor circuit voltage at the PCM
goes above 4.9 volts for more than 3 seconds.
ECT SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
ECT SENSOR GROUND CIRCUIT OPEN
ECT SENSOR SIGNAL CIRCUIT OPEN
ECT SENSOR
ECT WIRING HARNESS INTERMITTENT
POWERTRAIN CONTROL MODULE
TEST
1 Turn the ignition on.
With the DRB, read the PCM DTCs.
Is the Good Trip Counter for P0118 displayed and equal to zero?
Yes → Go To 2
→ Go To 7
No
2 Turn the ignition off.
Disconnect the ECT harness connector.
Start the engine and allow the engine to idle.
Measure the voltage on the ECT Sensor Signal circuit.
Is the voltage above 5.5 volts?
Yes → Repair the ECT Sensor Signal circuit for a short to voltage.
→ Go To 3
No
3 Turn the ignition off.
Disconnect the ECT Sensor harness connector.
Measure the resistance between ground and the ECT Sensor Ground circuit.
Is the resistance below 5.0 ohms?
Yes → Go To 4
→ Repair the ECT Sensor Ground circuit for an open.
No
POSSIBLE CAUSES
ACTION
Perform POWERTRAIN VERIFICATION TEST VER - 5.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
DRIVEABILITY - GAS
57
APPLICABILITY
All
All
All