TM 10-3930-675-24-1
ECU-TO-ECU COMMUNICATIONS TROUBLESHOOTING - CONTINUED
0014 00
Table 12. Error Code 684 - Communication Failure Between Transmission ECU (793) and Display ECU (795)
Troubleshooting Procedures.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Error Code 684 - Communication Failure 1. Perform troubleshooting steps
Between Transmission ECU (793) and Display
for error code 111 (WP 0113
ECU (795).
00).
NOTE
Ensure you disconnect and isolate each connector/cir-
cuit mentioned in error code 111 steps before checking
for continuity to ground.
2. Perform each continuity check Replace any wire found to have
for continuity to ground.
continuity to ground.
Table 13. Error Code 685 - Communication Failure Between Transmission ECU (793) and Steering ECU (792)
Troubleshooting Procedures.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Error Code 685 - Communication Failure 1. Check steering ECU (792) and Replace damaged connector or
Between Transmission ECU (793) and Steering
transmission ECU (793) for ECU (792), ECU (793) (WP 0080
ECU (792).
loose or damaged connectors. 00).
2. Check ECU (792) pins 159 and Tighten loose connections.
160 for loose connection.
3. Inspect jumpers between a. If continuity is not present,
terminal connections at X179.
repair any loose or missing
Check continuity and for
connections.
continuity to ground between b. Replace missing or damaged
(792) pin 159 and X179 pin L,
and between (792) pin 160 and c. Replace any grounded wire.
X179 pin H.
4. Check continuity and for a. If continuity is not present,
continuity to ground between
repair any loose or missing
X179 pin L and (793) pin 26,
connections.
and between X179 pin H and b. Replace any grounded wire.
(793) pin 25.
c. Replace ECU (793) (WP 0080
00).
d. Replace ECU (792) (WP 0080
00).
0014 00-13
