DaimlerChrysler Jeep Grand Cherokee 2002 Service Manual page 244

DRIVEABILITY - DIESEL
*ENGINE CRANKS BUT WILL NOT START —
TEST
8 Turn the ignition off.
Using the DRBIII 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 DRBIII .
Does the DRBIII display a steady clean CKP Signal pattern for each circuit?
Yes → Go To 9
→ Perform Test for DTC P0340-Crankshaft Position Sensor Circuit
No
9 Refer to the Service Information and perform the fuel pressure test.
Is the fuel pressure within specification?
Yes → Go To 10
→ Repair as necessary.
No
10 Refer to the Service Information and perform the fuel pressure test. Note the test
results.
Using the DRBIII , read the Fuel Pressure and compare the two readings.
Are the two readings within 3450 kPa (500 PSI) of each other?
Yes → Go To 11
→ Go To 13
No
11 Refer to the Service Information to ensure the Engine Drive Gears/Sprocket are
installed correctly and the camshaft and crankshaft gears are timed correctly.
Were any problems found?
Yes → Repair as necessary.
→ Go To 12
No
12 Inspect the fuel supply for contamination.
Is the fuel contaminated?
Yes → Check the fuel supply for contamination.
→ Replace and program the Engine Control Module in accordance
No
13 Turn the ignition off.
Disconnect the Fuel Pressure Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance of the Fuel Pressure Sensor Signal circuit.
Is the resistance below 10.0 ohms?
Yes → Go To 14
→ Repair the Fuel Pressure Sensor Signal circuit for an open.
No
ACTION
Dynamic Plausibility.
Perform NO START VERIFICATION - VER-1.
Perform NO START VERIFICATION - VER-1.
Perform NO START VERIFICATION - VER-1.
Perform NO START VERIFICATION - VER-1.
with the Service Information.
Perform NO START VERIFICATION - VER-1.
Perform NO START VERIFICATION - VER-1.
Continued
236
APPLICABILITY
All
All
All
All
All
All