DDEC TROUBLESHOOTING
10.10 ENGINE BRAKE INOPERATIVE
The following procedure will troubleshoot DDEC controlled Engine Brake Inoperative.
10.10.1 Engine Brake Inoperative
Perform the following steps to troubleshoot the inoperative engine brake:
1. Turn ignition ON.
2. Plug in DDR.
3. View Diagnostic Data List to see if the correct application is programmed into the ECM.
4. Next to Engine Brake, the display should read ON or OFF. If it reads N/A, the DDC
mainframe must be changed and the ECM must be reprogrammed after the change is made.
5. If the ECM is correctly configured, go to the view calibration area with the DDR and
check to ensure that the two required inputs (Engine Brake Low and Engine Brake
Medium) are configured.
6. If the inputs are not configured, or incorrectly configured, this must be corrected using the
DDEC reprogramming station.
7. If the inputs are configured correctly, print or write down the inputs and outputs for future
reference. Refer to section 10.10.2. Refer to the appropriate Application and Installation
manual for engine brake operation.
10.10.2 Check Switches
Perform the following steps to troubleshoot the switches:
1. Turn ignition ON.
2. Plug in DDR.
3. Select Switch Light status - Inputs.
4. View DDR display of Eng Brk Low and Eng Brk Med.
NOTE:
Set brake dash switch position on low.
[a] If Eng Brake Low is ON and Eng Brake Med is OFF, refer to section 10.10.3.
[b] If Eng Brake Low is ON and Eng Brake Med is ON, medium and low inputs are
shorted to each other. Repair. Refer to section 10.10.9.
[c] If Eng Brake Low is OFF and Eng Brake Med is ON, input wires are reversed.
Correct and refer to section 10.10.9.
[d] If Eng Brake Low is OFF and Eng Brake Med is OFF, refer to section 10.10.4.
5. Turn brake enable dash switch on.
All information subject to change without notice.
6SE497 9709 Copyright © 1997 DETROIT DIESEL CORPORATION
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