car won't pass 3rd gear with headlights on? but shifts passed 3rd with it off...
 

This car is a 99 maxima se auto with about 140k. the car had the problem prior to me buying the car, but i figured it'd be a simple fix. man was i wrong =/. soo the codes i originally had were the MAF sensor malfunction, and another P0705 code which was a bad neutral safety switch. i changed both the parts out, and still no fix. the problem is ONLY when i turn my headlights on. i could be driving at 80mph in 5th gear with my headlights off and as soon as i turn them on my rpms jump and the car is now stuck in 3rd gear. if i turn the headlights off and let go of the gas a bit it'll shift back into the correct gear. i have no more CEL fellas, TCM checked out fine, it's been it 3 mechanics, no clue...umm what should i check? the transmission is fine though. is it possible that i got a faulty wire somewhere?

Where are the headlights drawing power from?

well first off check all your fuses and relays as well as the wiring to your headlights, who knows mabey youve miraculosly got a ground for the headlights tripping a tranny related sensor and putting her into limp mode? idk thats all i got..

And how is it that you have a 4th gen A/T that has a 5th gear?

i figured i should of checked before i posted here, but i didn't know how to check all of my wiring or connections for the battery or what not.

typo... sorry. 4th gear.





sorry for not giving ya guys more to work with, if you guys tell me what to check, i can learn to figure it out. i follow the FSM but not everything in there is simple to understand =/

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:rollsmile

For starters, Fuse #4 (7.5A) is for your trans control module, you need a voltmeter to check the DC voltage at that fuse to ground. Check the voltage with the fuse in. This is the voltage going to the trans control module. If it was abnormally low I could see it causing a problem like this.

Check the voltage with and without the lights on. It should measure similar to your battery voltage with lights on and off. If there is a big difference more than 2-3 volts could cause the problem.


I can try and help but, If mechanics had the car and can't find it good luck over the org.

Cause could be ignition switch, trans module or a fault with one of the sensors that runs to the trans module. Or a wiring/power probem. I believe there are some diagnostics you can run on the trans in the FSM. I'm not sure, never got into that too much. You may want to search the org for that. Edit: forget it, just noticed you said trans checked out OK.

well i just did another CEL diagnosis and i came up with 1101 and 0604 which comes out to be Inhibitor Switch for 1101 and Cylinder 5 Misfire for 0604. i NEVER had these before. could any of these cause this problem maybe?

Probably not the misfire but the inhibit switch is related to the the trans, probably need to fix that. If your voltage from your battery to the ECU and or Trans module, are not a stable 12-13 VDC you could get all kinds of problems. That's why I suggest the voltage readings.

i'll check up on those first thing tomorrow morning and will let you guys know.oh btw, i read somewhere about checking if my revserse lights work or not, well they don't. if that helps...

Reverse lights are powered by the inhibitor switch. Fuse #13 (10Amp) is used for this circuit, check that. It's in the underdash fuse box. Explains the 1101 code. Could be if you fix this obvious problem it may help the headlight/shifting issue. Never know, could be related.

Did you mention the inhibitor/reverse lights issue to the mechanics? It's a simple circuit, if they cant fix that they don't have a clue.

Is OD/OFF lighting up when you turn your headlights on?
Does the OD/OFF switch work correctly when the headlights are off?

it works fine with and without the lights on.

i havn't gotten around to the other things, ill def get everything in by tomorrow. thank you for the help. def. appreciated.

im not going to read all of these posts but did he ever mention if he had a stable voltage coming from the alt, and stable under load as well?

WORD!!?? check your fuse and wiring harness, best bet is probably change out all of your fuses correctly then if that doesnt work, change your wiring harness..

:confused:

Changing fuses won't do a single thing unless you are using the wrong ones and blowing them. Occasionally re-seating a connector or board will fix a problem but simply replacing fuses is not worth their low cost. And you can trace the harness to find a chafed, broken wire but replacing a harness isn't something you just do without a real good reason, like a flooded car or an engine swap. They aren't cheap and they are integrated into the whole engine bay/motor.

the od light could be wired within the switch.
it does seem like when you turn on the headlight it's possible it's sending a signal to the tcu thinking to turn off the OD.

i say look up the wiring diagram and see if the headlight is within the same wireloom as the tcu

Im glad u mentioned that, gave me the brains to go play with my OD, problem aint fixed but when im driving with my lights off and tutrned my OD on it did the same thing it would as if driving and turning my headlights on... soo... im assuming when i turn my headlights on it's also enabling my OD. But my OD light does not turn on unless i push the button myself. And when i drive with my headlights on and enable OD the light turns on but nuttin different happens. I kno i havnt responded about the voltages, ive been busy n using a different car. N the ohms reader is at a friends house. Ne way lemme kno wat u guys think or suggest.

well the light could be within the same circuit as the switch.
so it's possible that the light wont come on unless the switch is on completing the circuit.

alright... so i downloaded the electrical fsm and engine fsm, i can't find anything on the overdrive.. is it posssible i skipped over it or did i waste my time? i checked it over about 3x and found nuttin. umm i am 100% convinced that it is my overdrive that is causing my problem. i can't find the wiring layout for my overdrive. i just want to be able to keep my OD on for the highway at night, bc otherwise i always have to drive 40mph on the highway bc i can't turn my headlights off =/

did you look at the tcu fsm?

yyessssnnoooo... =/ brb. gotta take a... piss? yeah brb. lol

soo from reading up on thsi issue, my OVERDRIVE does not enable with my headlights on. but the yellow "od" light does not turn on with the headlights on. if i press the button it will turn off n on as i please. but the tourque converter stays locked in 3rd gear. wow i've done soo much reading with no solution, still looking for the TCM FSM and can't find it no where. can anyone help me with this?

lmfao!!!

You need to look in the AT section of the FSM. You can probably forget about the voltages for now. The AT section has information that should help you troubleshoot if you have issues with the OD. From your description I can't determine if your overdrive is working properly or not.

i want to say it works perfectly fine... but how the hell did it get mixed up with the headlights disabling my OD without letting me know? because with my headlights off... EVERYTHING drives exactly how it should. my OD works fine too with the headlights off. it's only with the lights on... if i turn my lights off and hold my highbeams on i can drive with my OD on still too.

can someone link me to the AT in FSM? the one on phmor sig don't work no more... =/

So you are saying that your OD turns off when you have the headlights on? Does the OD light go off when the headlights are turned on or just the the trans drops out of OD?

sry, i know i twisted up my words a bit.

by "OD" being ON, the OD indicator light is off

by OD being off, the OD indicator light is on

headlights on = OD is off (not allowing to shift into 4th gear which is the "OVERDRIVE" gear and the OD light is off as well. (won't pass 3rd gear)

headlights off = OD is on and the OD light is off. (shifts 100% from 1st-4th gear)

the "OD LIGHT" turns on and off whenever i push the button.

hope that clarifies it all.



can someone link me to the AT FSM? did a search and found a few dead links. it's help me alot if anyone can provide this for me. thank you in advance.

ty so much