DDEC TROUBLESHOOTING
Step
Cruise
Enable
Switch
Set /
Coast
Switch
Res /
Accel
Switch
DDR
Readout
Being
Looked At
DDR
Display
Okay
Go To
1.
On
Off
Off
Set/Coast
On
Off On
Yes No
Refer to
step 2 Refer
to section
10.7.11
2.
On
On
Off
Set/Coast
On
Off On
No Yes
Refer to
section
10.7.12
Refer to
step 3
3.
On
Off
Off
Res/Ac-
celOn
Off On
Yes No
Refer to
step 4 Refer
to section
10.7.13
4.
On
Off
On
Res/Accel
On
Off On
No Yes
Refer to
section
10.7.14Refer
to section
10.7.15
Table 10-5
Cruise Control Quick Check Table III, Check Out Set/Coast and
Resume/Accel Switches and Wiring (Ignition ON Not Running)
10.7.5
Check for Short at the Cruise Enable Circuit
Perform the following steps to check for a short at the cruise enable circuit:
1. Turn ignition ON.
2. Turn cruise engage switch to off.
3. Disconnect the vehicle harness connector at the ECM.
4. Measure resistance between the cruise enable cavity (i.e. F2) on the vehicle harness
connector and a good ground.
[a] If the resistance measurement is less than or equal to 10,000 , reconnect the
vehicle harness. Turn the ignition on. Then run steps listed in Table 10-4; and
listed in Table 10-5. If any DDR display received is not okay, refer to the indicated
step. If all steps listed in Table 10-4 and listed in Table 10-5, pass, then the cruise
engage wire is shorted to the ground. Repair the short, or replace the switch.
Refer to section 10.7.16.
[b] If the resistance measurement is greater than 10,000 , refer to section 10.7.2.
10.7.6
Check for Open at the Cruise Enable Circuit
Perform the following steps to check for an open at the cruise enable circuit:
All information subject to change without notice.
6SE497 9709 Copyright © 1997 DETROIT DIESEL CORPORATION
10-31
