2002 QX4 Transmission Issue

[Israelpr]

The electronic O/D does not work. It lights on/off but the transmission stays the same (no change in revs). Also when I manually shift into 1st gear the transmission does not shift (no change in revs). All others gears work fine (reverse, parking, neutral and the Manual second gear). It also shifts normally when driven on the "Drive" gear. Any ideas what it can be? (I just had the main oil seal changed which required bringing down the transmission to do the repair, don't know if this has to do anything with the issue at hand). Thanks.

[mdmellott]

When you manually move the shift lever to the 1st gear position, do you feel the lever engage in the detent the same way you can feel it engage the detents at the other positions R, N, D, and 2? If not, the shift cable manual control linkage was not adjusted properly when your transmission was reinstalled after you had the main seal repair done. Be sure it feels totally engaged in the detent at the 1st gear position and not just barely dropping into position. When fully engaged, the lever should be able to be freely rocked slightly back and forth just like it feels in all the other positions. Also, double check the ATF level while the engine is running and after you have cycled the shift lever through all the gear positions. Hold the shift lever at each position for about 10 seconds and then put it back in Park before checking the fluid level on the dipstick.

[Israelpr]

When I shift the lever to the first gear it definitely engages in the detent the same way the it engages in R, N, D and 2. What it does not do is "work" on first gear (no reduction in speed and no difference in revs). Double checked the ATF level as you suggested and all is well. Don't want to confuse the issue but the O/D doesn't work either. The light comes on/off when you press the button on the shift lever, but it does nothing (no increased revs) and the light on the dash that shows what shift you're on is off. Could these things be related? Thanks for the help my friend.

[mdmellott]

the light on the dash that shows what shift you're on is off. Could these things be related?

Another symptom. Yes, all those things could be related. It is time for a deep dive into the diagnostics to figure this out. Your transmission range switch on the PNP switch or the TCM may have an issue. There are some things you may be able to do to diagnose what faults may have been detected by your onboard diagnostic system. The following link to the AT section of the factory service manual will help you with that. https://www.nicoclub.com/service-manual ... 002/AT.pdf However, I am suspecting your mechanic may have done something or not done something they should have when the previous work was done. I would take it back and have them fix it and insist there be no additional cost for this diagnosis and repair.

[Israelpr]

Took the QX4 to the mechanic that installed the main oil seal. You were right! He made a mistake and did not attach some electrical connections to the transmission when it was reinstalled. In 20 minutes everything was installed and back to normal. Again, thanks for your time and logic, I appreciate it.