DDEC TROUBLESHOOTING
10.15 TRANSMISSION INTERFACE FAULT
Numerous transmissions utilize the DDEC ECM to receive signals that are used to determine
shift points, and/or other information.
10.15.1 Transmission Fault
Transmissions that currently utilize data links:
J1587 - Allison World Transmissions
J1939 Eaton, Allison
J1922 Ceemat
Advanced Interface
ESS ™, Rockwell - Refer to ESS Troubleshooting Manual
Top2, Eaton - Refer to MISC Output Troubleshooting
PWM Signal Type - DDEC provides a PWM signal that is used by the transmission or
its components
10.15.2 Verify Transmission Type
Perform the following steps to check the transmission type.
1. Turn ignition ON.
2. Plug in DDR.
3. Check transmission origination.
[a] If a manual transmission, Allison hydraulic, Allison Electronic, Voith, ZF,
refer to section 10.15.3.
[b] If a J 1939/autoshift, Allison WT, Rockwell RXX-X, refer to the troubleshooting
guide of the transmission manufacturer to troubleshoot the fault.
[c] If the transmission type does not match the transmission correctly, reprogram and
refer to section 10.15.4.
10.15.3 Review PWM #1 Signal
Perform the following steps to check the DDR for codes.
1. Perform road test with assistant.
2. Plug in DDR.
3. Watch PWM #1 signal.
[a] If the PWM varies with the load changes, Alison Electric, Voith or ZF, the signal is
normal. Review the wiring or transmission.
[b] If the PWM signal is 0% or 100% when the signal is for Allison Hydraulic with
load changes, the program is normal. Review the transmission, wiring or relay.
Refer to section 10.15.4.
All information subject to change without notice.
6SE497 9709 Copyright © 1997 DETROIT DIESEL CORPORATION
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