DDEC TROUBLESHOOTING
6.1
BASICS
CHANGES NEEDED. The following listed items should be checked prior to starting any
troubleshooting:
Ensure engine serial number on the ECM matches the serial number on the cylinder block.
Walk around the vehicle. Look for obvious problems such as leaks (air or liquid).
Inspect ECM for worn isolators, debris or bolts lodged between ECM and cylinder block.
Broken wiring connectors.
Fuel Supply - Full on.
Fuel tank level.
Vehicle damage.
Investigate into any prior repairs, if applicable.
Check for poor mating of the connector halves or terminals not fully seated in the
connector body (backed out terminals).
Look for improperly formed or damaged terminals. All connector terminals in the problem
circuit should be carefully inspected to determine proper contact tension. Use a mating
terminal to test the contact tension.
Electrical system interference caused by a defective relay, ECM driven solenoid, or a
switch causing an electrical surge. Look for problems with the charging system (alternator,
etc.). In certain cases, the problem can be made to occur when the faulty component is
operated as in the case of a relay.
Verify alternator grounds are clean and making good contact. Disconnect the alternator
belt to test.
Wiggle wires and harnesses to try to make the problem active, or re-occur.
All information subject to change without notice.
6SE497 9709 Copyright © 1997 DETROIT DIESEL CORPORATION
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