DaimlerChrysler Jeep Grand Cherokee 2002, Service Manual

Page: 155 / 284

TEST ACTION APPLICABILITY
2 Turn the ignition on.
With the DRBIII
t
in Sensors, monitor the Accelerator Pedal Position and Boost
Pressure Sensors only.
One at a time while monitoring the DRB sensor readings, disconnect then reconnect
the Boost Pressure, Accelerator Pedal Position, A/C Pressure and Engine Oil
Pressure Sensor harness connectors.
WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
Start the engine.
NOTE: If one of the sensors is shorted to ground internally, disconnecting it
will cause the voltage reading on the DRB to rise for the monitored sensor
that has not been disconnected.
NOTE: Disconnecting components will generate new DTCs which should be
ignored.
Did either of the monitored sensor voltage readings rise when one sensor was
disconnected?
All
Yes
→
Replace the Sensor that, when disconnected, caused the DRB
sensor readings to rise.
Perform ROAD TEST VERIFICATION - VER-2.
No
→
Go To 3
3 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Boost Pressure, A/C Pressure and Engine Oil Pressure Sensors
harness connectors.
Measure the resistance between ground and the Sensor Reference Voltage B circuit.
Is the resistance above 100 kohms? All
Yes
→
Go To 4
No
→
Repair the Sensor Reference Voltage B circuit for a short to
ground.
Perform ROAD TEST VERIFICATION - VER-2.
4 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Engine Oil Pressure Sensor harness connector.
Measure the resistance between the Sensor Reference Voltage B circuit and the Oil
Pressure Sensor Ground circuit.
Disconnect the Boost Pressure Sensor harness connector.
Measure the resistance between the Sensor Reference Voltage B circuit and the Boost
Pressure Sensor Ground circuit.
Disconnect the A/C Pressure Sensor harness connector.
Measure the resistance between the Sensor Reference Voltage B circuit and the A/C
Pressure Sensor Ground circuit.
Is the resistance above 100 kohms for each measurement? All
Yes
→
Go To 5
No
→
Repair the Sensor Reference Voltage B circuit for a short to the
Sensor Ground circuit that measured below 100 kohms.
Perform ROAD TEST VERIFICATION - VER-2.
147
DRIVEABILITY - DIESEL
P0651-SENSOR REFERENCE VOLTAGE B CKT VOLTAGE TOO LOW —
Continued
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