DaimlerChrysler Jeep Grand Cherokee 2002 Service Manual page 32

DRIVEABILITY - DIESEL
P0100-MASS AIR FLOW SENSOR SIGNAL VOLTAGE TOO HIGH —
Continued
TEST
13 Turn the ignition off.
Disconnect the MAF Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance between ground and the Sensor Reference Voltage A circuit
at the MAF harness connector.
Is the resistance below 1000 ohms?
Yes → Repair the Sensor Reference Voltage A circuit for a short to
→ Go To 14
No
14 Turn the ignition off.
Disconnect the MAF Sensor harness connector.
Disconnect the ECM harness connectors.
Remove the ASD Relay from the PDC.
Connect a jumper wire between cavity 30 and cavity 87 of the ASD Relay connector.
Turn the ignition on.
Measure the voltage of the Sensor Reference Voltage A circuit in the ECM harness
connector.
Is the voltage above 1.0 volt?
Yes → Repair the Sensor Reference Voltage A circuit for a short to
→ Go To 15
No
15 Turn the ignition off.
Disconnect the Fuel Pressure Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance between the 5-volt Supply circuit and the Sensor Ground
circuit at the Fuel Pressure Sensor harness connector.
Is the resistance above 1000 ohms?
Yes → Go To 16
→ Repair the Fuel Pressure Sensor 5-volt Supply circuit for a short
No
16 Turn the ignition off.
Disconnect the Fuel Pressure Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance between ground and the 5-volt Supply circuit at the Fuel
Pressure Sensor harness connector.
Is the resistance below 1000 ohms?
Yes → Repair the Fuel Pressure Sensor 5-volt Supply circuit for a short
→ Go To 17
No
ACTION
ground.
Perform ROAD TEST VERIFICATION - VER-2.
voltage.
Perform ROAD TEST VERIFICATION - VER-2.
to the Sensor Ground circuit.
Perform ROAD TEST VERIFICATION - VER-2.
to ground.
Perform ROAD TEST VERIFICATION - VER-2.
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APPLICABILITY
All
All
All
All