DaimlerChrysler Jeep Grand Cherokee 2002 Service Manual page 49

P0190-FUEL PRESS SENSOR CIRCUIT MALF SIGNAL VOLTAGE TOO
HIGH —
Continued
TEST
2 Turn the ignition off.
Disconnect the Fuel Pressure Sensor harness connector.
Turn the ignition on.
Measure the voltage of the Fuel Pressure Sensor Signal circuit.
Select the appropriate voltage reading.
Voltage is above 5.5 volts.
Voltage is between 4.7 and 5.4 volts.
Voltage is below 4.7 volts.
3 Turn the ignition off.
Disconnect the Fuel Pressure 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 Fuel Pressure Sensor Signal circuit.
Is the voltage below 1.0 volt?
Yes → Replace and program the Engine Control Module in accordance
→ Repair the Fuel Pressure Sensor Signal circuit for a short to
No
4 Turn the ignition off.
Disconnect the Fuel Pressure Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance of the Sensor Ground circuit.
Is the resistance below 5.0 ohms?
Yes → Go To 5
→ Repair the Sensor Ground circuit for an open.
No
5 Turn the ignition off.
Disconnect the Fuel Pressure Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance of the 5-Volt Supply circuit.
Is the resistance below 5.0 ohms?
Yes → Go To 6
→ Repair the 5-volt Supply circuit for an open.
No
ACTION
Go To 3
Go To 4
Go To 9
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
voltage.
Perform ROAD TEST VERIFICATION - VER-2.
Perform ROAD TEST VERIFICATION - VER-2.
Perform ROAD TEST VERIFICATION - VER-2.
DRIVEABILITY - DIESEL
41
APPLICABILITY
All
All
All
All