B1739 - Driver Mirror Horizontal Switch Short To Battery

DTC B1739 - Driver Mirror Horizontal Switch Short To Battery

NOTE: Ford DOES NOT provide a procedure to perform the following pinpoint test without the Rotunda New Generation Star (NGS) tester 007-00500 or equivalent.

B1739-1 - Make Sure Switches Are Not Pressed

- Turn ignition switch to RUN.
- Turn ignition switch OFF. These two steps "wake up" the driver seat module.
- Open driver side door. This disables delay accessory function.

NOTE: Seat will move a short distance in each direction during self-test.

- Execute self-test.
- Make sure that driver and passenger mirror switches are not pressed.
- Clear DTCs.
- Rerun self-test diagnostics. Be sure that no switches are pressed during test.

Is DTC B1739 still present?

YES GO to B1739-3.
NO G0 to B1739-2.

B1739-2 - Make Sure Switches Are Not Sticking

- Make sure ignition remains OFF.
- Set Rotunda New Generation Star (NGS) Tester 007-00500 or equivalent to read PID DMIR_H.
- Press the driver mirror switch in the horizontal position several times and observe the display.

Does PID show the button releases within 1 second when the switch is released?

YES System operating normally. Continuous DTC would be set if mirror switch held for more than 2 minutes.
NO REPLACE mirror switch. RESTORE vehicle. RETEST system.

B1739-3 - Test Mirror Switch

- Disconnect mirror switch. Make sure that all other connections are still intact.
- Clear DTCs.
- Rerun self-test diagnostics.

Is DTC B1739 still present?

YES GO to B1739-4.
NO REPLACE mirror switch. RESTORE vehicle. RETEST system.

B1739-4 - Check Circuit 942 (R/O)

- Disconnect driver seat module connector C1.
- Using a voltmeter connected to a known good ground, test pin C1-5, circuit 942 (R/O) for voltage.

Is battery positive voltage (B+) present?

YES SERVICE Circuit 942 (R/O) for short to B+. RESTORE vehicle. RETEST system.
NO REPLACE driver seat module. RESTORE vehicle. RETEST system.