P1904
DTC P1904: Open in Auxiliary Transmission Fluid Pump (ATFP) Motor W-phase 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. Choose ATFP Motor Test in Miscellaneous Test Menu, and check that the DTC indicates.
Are DTC P1902, P1903, and P1904 indicated simultaneously?
YES - Go to step 3.
NO - Only DTC P1904 is indicated, go to step 6. If no DTCs recur, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the ATFP control unit and the ATFP motor.
3. Turn the ignition switch OFF.
4. Disconnect the ATFP control unit connector.
5. Check for continuity between ATFP control unit connector terminal No. 4 and body ground.
Is there continuity?
YES - Replace the ATFP control unit, then go to step 11.
NO - Repair an open in the Wire between ATFP control unit connector terminal No. 4 and ground (G501), or repair poor ground (G501), then go to step 11.
6. Turn the ignition switch OFF.
7. Disconnect the ATFP control unit connector and ATFP motor connector.
8. Inspect the connectors and connector terminals to be sure they are making good contact.
Are the connector terminals OK?
YES - Go to step 9.
NO - Repair the connector terminals, then go to step 9.
9. Check for continuity between ATFP control unit connector terminal No. 6 and ATFP motor connector terminal No. 2.
Is there continuity?
YES - Go to step 10.
NO - Repair an open in the wire between ATFP control unit connector terminal No. 6 and the ATFP motor connector, then go to step 11.
10. Check for continuity between ATFP motor connector terminals No. 1 and No. 2.
Is there continuity?
YES - Replace the ATFP control unit, then go to step 11.
NO - Replace the ATFP, then go to step 11.
11. Clear the DTC with the HDS.
12. Warm up the engine to normal operating temperature (the radiator fan comes on).
13. Drive the vehicle in the D position. Slow down and stop the wheels in auto idle stop.
14. Monitor the OBD status for P1904 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 6 and recheck.