U1260
DTC U1260: Problem in PCM-to-ATFP Control Unit Communication CircuitNOTE:
^ Record all freeze data and review General Troubleshooting Information before you troubleshoot.
^ This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.
1. Clear the DTC with the HDS.
2. Turn the ignition switch ON (II), wait for more than 10 seconds, then check that DTC U1260 recurs. is DTC U1260 indicated?
YES - Go to step 3.
NO - Intermittent failure, the system is OK at this time.
3. Turn the ignition switch OFF.
4. Check for loose or poor connections at PCM connector terminal D2 and ATFP control unit connector terminal No. 9.
Is the connection OK?
YES - Go to step 5.
NO - Connect the connectors securely, return to step 1 then recheck.
5. Jump the SCS line with the HDS.
6. Disconnect PCM connector D (17P).
7. Disconnect ATFP control unit connector.
8. Check for continuity between ATFP control unit connector terminal No. 9 and body ground.
Is there continuity?
YES - Repair a short in the wire between PCM connector terminal D2 and the ATFP control unit, then go to step 1 B.
NO - Go to step 9.
9. Check for continuity between PCM connector terminal D2 and ATFP control unit connector terminal No. 9.
Is there continuity?
YES - Go to step 10.
NO - Repair an open in the wire between PCM connector terminal D2 and the ATFP control unit, then go to step 18.
10. Remove the ATFP control unit, and substitute a known-good ATFP control unit.
11. Connect ATFP control unit connector, and PCM connector D (17P).
12. Clear the DTC with the HDS.
13. Turn the ignition switch ON (II), wait for more than 10 seconds, then check that DTC U1260 recurs.
Is DTC U1260 indicated?
YES - Go to step 14.
NO - Replace the original ATFP control unit, then go to step 18.
14. Turn the ignition switch OFF.
15. Disconnect ATFP control unit connector.
16. Turn the ignition switch ON (II).
17. Measure the voltage between ATFP connector terminal No. 10 and body ground.
Is there battery voltage?
YES - Replace the PCM, go to step 18.
NO - Check for a blown No. 18 fuse in the underdash fuse/relay box. If the fuse is OK, repair an open in the wire between ATFP control unit connector terminal No. 10 and the under-dash fuse/relay box, then go to step 18.
18. Clear the DTC with the HDS.
19. Turn the ignition switch ON (II), and wait for more than 10 seconds.
20. Monitor the OBD status for U1260 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.
Does the result indicate PASSED?
YES - Troubleshooting is complete.
NO - Return to step 4 and recheck.