DaimlerChrysler Jeep Grand Cherokee 2002, Service Manual

Page: 81 / 284

TEST ACTION APPLICABILITY
6 Turn the ignition off.
Disconnect the CKP 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 both CKP Sensor Signal circuits.
Is the voltage below 1.0 volt for both measurements? All
Yes
→
Go To 7
No
→
Repair the CKP Sensor Signal circuit(s) for a short to voltage.
Perform ROAD TEST VERIFICATION - VER-2.
7 Turn the ignition off.
Using the DRB lab scope, backprobe both of the CKP Sensor Signal circuits at the
ECM harness connector.
NOTE: Refer to Charts and Graphs to view a correct CKP Sensor signal.
Start the engine, if the engine will not start, crank the engine for several seconds
while monitoring the DRB.
Does the DRB display a steady clean CKP Signal pattern for each circuit? All
Yes
→
Go To 8
No
→
Replace the Crankshaft Position Sensor.
Perform ROAD TEST VERIFICATION - VER-2.
8 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the CKP Sensor harness connector.
Measure the resistance of the Shield circuit.
Is the resistance below 10.0 ohms? All
Yes
→
Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No
→
Repair the Shield circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
73
DRIVEABILITY - DIESEL
P0340-CMP/CKP POSITION SENSOR CIRCUIT - CKP DYNAMIC PLAUSI-
BILITY —
Continued
ProCarManuals.com