DDEC TROUBLESHOOTING
72.3 TROUBLESHOOTING FLASH CODE 72
The following procedure will troubleshoot Flash Code 72.
72.3.1
Overspeed
Perform the following steps to troubleshoot overspeed.
1. These codes indicate the vehicle speed has exceeded the limits programmed into the ECM.
Verify cruise control and VSS information.
[a] Code 84/0 - Overspeed with fuel limit has been exceeded.
[b] Code 84/11 - Overspeed without fuel limit has been exceeded.
2. Limits are a reasonable distance above the road speed limit.
[a] If the limits are a reasonable distance, go to step 3
[b] If the limits are not a reasonable distance above the road speed limit, change the
limits and perform the test. Refer to section 72.3.2.
NOTE:
For information regarding overspeed limits, refer to section 7.1.29.
3. Fuel Economy Incentive feature configured recently.
[a] If configured recently, review the limits. W/FEI limits may need to be increased.
[b] If not configured recently, the conditions are normal. The vehicle has exceeded
speed limits set.
72.3.2
Test
Perform the following steps to troubleshoot overspeed.
1. Start and run the engine.
2. Perform a road test.
[a] If the overspeed condition has disappeared, troubleshooting is complete.
[b] If the overspeed condition still exists, review this section from the beginning to
find the error. Refer to section 72.3.1.
All information subject to change without notice.
6SE497 9709 Copyright © 1997 DETROIT DIESEL CORPORATION
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