DaimlerChrysler Jeep Grand Cherokee 2002 Service Manual page 31

P0100-MASS AIR FLOW SENSOR SIGNAL VOLTAGE TOO HIGH —
Continued
TEST
9 Turn the ignition off.
Disconnect the MAF Sensor harness connector.
Turn the ignition on.
Measure the voltage between the 5-volt Supply circuit and the Sensor Ground circuit
at the MAF Sensor harness connector.
Is the voltage above 4.5 volts?
Yes → Go To 10
→ Replace and program the ECM in accordance with the Service
No
10 Turn the ignition off.
Disconnect the MAF Sensor harness connector.
Turn the ignition on.
Using a 12-volt test light connected to ground, probe the ASD Relay Output circuit in
the MAF Sensor harness connector
Does the test light illuminate brightly?
Yes → Replace the MAF Sensor.
→ Repair the ASD Relay Output circuit for an open.
No
11 Turn the ignition off.
Disconnect the MAF Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance of the Sensor Reference Voltage A circuit.
Is the resistance below 10.0 ohms?
Yes → Go To 12
→ Repair the Sensor Reference Voltage A circuit for an open.
No
12 Turn the ignition off.
Disconnect the MAF Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance between the Sensor Reference Voltage A circuit and the
Sensor Ground circuit at the MAF Sensor harness connector.
Disconnect the Accelerator Pedal Position Sensor harness connector.
Measure the resistance between the Sensor Reference Voltage A circuit and both
Accelerator Pedal Position Sensor Ground circuits.
Is the resistance above 100 kohms for both measurements?
Yes → Go To 13
→ Repair the Sensor Reference Voltage A circuit for a short to the
No
ACTION
Information.
Perform ROAD TEST VERIFICATION - VER-2.
Perform ROAD TEST VERIFICATION - VER-2.
Perform ROAD TEST VERIFICATION - VER-2.
Perform ROAD TEST VERIFICATION - VER-2.
Sensor Ground circuit.
Perform ROAD TEST VERIFICATION - VER-2.
DRIVEABILITY - DIESEL
23
APPLICABILITY
All
All
All
All