DDEC TROUBLESHOOTING
1. Check the terminals at the vehicle harness and 5-way power harness connectors (both
ECM and harness side) for damage: bent, corroded and unseated pins or sockets.
See Figure 10-7.
[a] If terminals and connectors are okay, replace the ECM. Refer to section 10.5.8.
[b] If the terminals and connectors are damaged, repair them. Refer to section 10.5.8.
Figure 10-7
ECM Vehicle Harness Connector
10.5.4
Check for Open
Perform the following steps to check for an open:
1. Turn ignition OFF.
2. Place a jumper wire across pins A (#900) and B (#901) of the DDL connector. Unplug the
vehicle harness connector and measure resistance between sockets C1 and C2.
3. Turn ignition ON, and again measure resistance between sockets C1 and C2.
See Figure 10-8.
[a] If both readings are greater than 5
, one or both data wires (circuit #900 or #901)
are open. Repair the open and refer to section 10.5.8.
All information subject to change without notice.
6SE497 9709 Copyright © 1997 DETROIT DIESEL CORPORATION
10-23
