Checking The Ecm Power And Ground Circuits - DaimlerChrysler Jeep Grand Cherokee 2002 Service Manual

Symptom:

*CHECKING THE ECM POWER AND GROUND CIRCUITS

ASD RELAY OUTPUT CIRCUIT(S) OPEN
ECM GROUND CIRCUIT(S) OPEN
FUSED ASD RELAY BATTERY SUPPLY CIRCUIT OPEN
FUSED IGNITION SWITCH OUTPUT CIRCUIT OPEN
TEST
1 Turn the ignition off.
Disconnect the ECM harness connectors.
Using a 12-volt test light connected to 12-volts, check both of the ECM ground
circuits in ECM harness connector C1 cavities 1 and 2.
Did the test light illuminate for both cavities?
Yes → Go To 2
→ Repair the ECM Ground circuit(s) for an open.
No
2 Turn the ignition off.
Disconnect the ECM harness connectors.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the Fused Ignition Switch
Output circuit in ECM harness connector C1 cavity 22.
Is the test light on?
Yes → Go To 3
→ Repair the Fused Ignition Switch Output circuit for an open.
No
3 Turn the ignition off.
Remove the ASD Relay from the PDC.
Using a 12-volt test light connected to ground, check the Fused ASD Relay Battery
Supply circuit in ASD Relay connector cavity 30.
Is the test light on?
Yes → Go To 4
→ Repair the Fused ASD Relay Battery Supply circuit for an open.
No
4 Turn the ignition off.
Disconnect the ECM harness connectors.
Remove the ASD Relay from the PDC.
Connect a jumper wire between cavity 30 and cavity 87 in the ASD Relay connector.
Using a 12-volt test light connected to ground, check the ASD Relay Output circuit in
ECM harness connector C1 cavities 4 and 5.
Did the test light illuminate for both circuits?
Yes → Test Complete.
→ Repair the ASD Relay Output circuit(s) for an open.
No
POSSIBLE CAUSES
ACTION
Perform ROAD TEST VERIFICATION - VER-2.
Perform ROAD TEST VERIFICATION - VER-2.
Perform ROAD TEST VERIFICATION - VER-2.
Perform ROAD TEST VERIFICATION - VER-2.
DRIVEABILITY - DIESEL
219
APPLICABILITY
All
All
All
All