ATP Light, 4LO light flashing, and can't shift into Gear
ATP Light, 4LO light flashing, and can't shift into Gear
As title says, my 1999.5 QX4 will not go into any gear or park. When I have the engine running and try to put it into P,there is a bad grinding coming from the transfer case or transmission. Before it locked itself out of gear, the 4WD warning light would sometimes turn on until the car was turned off. Also, the ATP light had just started coming on upon startup, and the 4LO light started flashing. Now, the ATP and 4LO are on and I can't put the car in gear; it can be pushed when the shifter is in the P position. Right before the ATP lighted turned on, the 4WD mode and 4WD warning were flickering back and forth - makes it seem like it could be an electrical problem with the transfer case failing to change modes when the dial is turned... What do yall think?
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rgk
- Posts: 588
- Joined: Tue Dec 23, 2014 4:48 am
- Car: 02 Pathfinder LE 3.5 auto 4x4
- Location: Indiana Dunes National Park
Re: ATP Light, 4LO light flashing, and can't shift into Gear
Here is the procedure for extracting automatic transmission trouble codes, according to the Pathfinder Haynes manual. You have to follow each step precisely:
1. Remove the vacuum hose from the throttle opener and connect a hand-held vacuum pump to it. Apply full vacuum and make sure it holds.
2. Turn the ignition key to OFF.
3. If you're working on a 2000 or earlier model, turn the ignition switch to ACC.
4. Pry off the shift lock release knob cover on the shift indicator cover, then insert a narrow screwdriver into the hole and push it down. Now move the shift lever into the D position.
5. Turn the ignition switch to the ON position, but don't start the engine.
6. Push the O/D switch in and hold it there, then turn the ignition key OFF, then ON again. Release the O/D switch (the light should go out).
7. Wait for at least two seconds, then move the shift lever to the 2 position.
8. Push the O/D switch in then release it (the light should go ON).
9. Push the O/D switch in and hold it depressed, move the shift lever to the 1 position, then release the switch.
10. Push the O/D switch in again - the light should go ON.
11. Push the O/D switch in again - the light should go OFF.
12. Push the O/D switch in and hold it depressed, push the accelerator pedal all the way to the floor, then release it, then release the O/D switch.
The computer is now in its output mode. It will begin displaying any stored trouble code(s) by flashing the O/D OFF indicator light in a sequence of long and short flashes specific to each stored code.
If all monitored circuits are operating correctly, you will see one long flash, followed by one long pause, followed by ten short flashes (twelve on 2001 and later Pathfinder models) of equal duration with short pauses of equal duration between them.
Extract your trouble code and report back here, I'll let you know what it means.
1. Remove the vacuum hose from the throttle opener and connect a hand-held vacuum pump to it. Apply full vacuum and make sure it holds.
2. Turn the ignition key to OFF.
3. If you're working on a 2000 or earlier model, turn the ignition switch to ACC.
4. Pry off the shift lock release knob cover on the shift indicator cover, then insert a narrow screwdriver into the hole and push it down. Now move the shift lever into the D position.
5. Turn the ignition switch to the ON position, but don't start the engine.
6. Push the O/D switch in and hold it there, then turn the ignition key OFF, then ON again. Release the O/D switch (the light should go out).
7. Wait for at least two seconds, then move the shift lever to the 2 position.
8. Push the O/D switch in then release it (the light should go ON).
9. Push the O/D switch in and hold it depressed, move the shift lever to the 1 position, then release the switch.
10. Push the O/D switch in again - the light should go ON.
11. Push the O/D switch in again - the light should go OFF.
12. Push the O/D switch in and hold it depressed, push the accelerator pedal all the way to the floor, then release it, then release the O/D switch.
The computer is now in its output mode. It will begin displaying any stored trouble code(s) by flashing the O/D OFF indicator light in a sequence of long and short flashes specific to each stored code.
If all monitored circuits are operating correctly, you will see one long flash, followed by one long pause, followed by ten short flashes (twelve on 2001 and later Pathfinder models) of equal duration with short pauses of equal duration between them.
Extract your trouble code and report back here, I'll let you know what it means.
Re: ATP Light, 4LO light flashing, and can't shift into Gear
Thanks for the transmission diagnostic. It's actually a transfer case issue. I ran the TC diagnostic and it came back with 21 flashes.
Again yesterday, the TC locked itself in neutral and then 4LO again with the 4WD light illuminated. I think there's a short with the engagement of 4WD. There's a gremlin in there somewhere randomly engaging the 4WD and then not recognizing the 4WD switch to get it out of 4LO.
Any ideas on how to fix or what the 21 code means?
Again yesterday, the TC locked itself in neutral and then 4LO again with the 4WD light illuminated. I think there's a short with the engagement of 4WD. There's a gremlin in there somewhere randomly engaging the 4WD and then not recognizing the 4WD switch to get it out of 4LO.
Any ideas on how to fix or what the 21 code means?
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rgk
- Posts: 588
- Joined: Tue Dec 23, 2014 4:48 am
- Car: 02 Pathfinder LE 3.5 auto 4x4
- Location: Indiana Dunes National Park
Re: ATP Light, 4LO light flashing, and can't shift into Gear
Do you mean to say you have a 2001.5?
I assume you performed the diagnostic procedure published in the service manual on page TF-28. TF-29 states that a flicker pattern of 21 flashes is caused by the following:
Transfer control device actuator circuit is faulty (Abnormalities are detected when motor relay circuit is open/shorted or relay monitor circuit is open/shorted.)
Check the following:
Actuator motor, actuator motor arm position sensing switch and their associated circuits, TF-114, TF-115 and
TF-94.
The transfer case section of the service manual for a 2001.5 QX4 can be downloaded here: http://www.nicoclub.com/FSM/QX4/2001.5_QX4/tf.pdf
Or do you have a 1999?
I don't see a method for self-diagnosis without using Nissan's proprietary CONSULTII hardware in the 1999 shop manual. In any case, here is a link to the 1999 shop manual, transfer case: http://www.nicoclub.com/FSM/QX4/1999/TF.pdf
The ATX transfer case is difficult enough that Haynes refuses to publish any help for it. That said, you at least have some info to arm yourself with when stepping foot in the shop. Good luck.
I assume you performed the diagnostic procedure published in the service manual on page TF-28. TF-29 states that a flicker pattern of 21 flashes is caused by the following:
Transfer control device actuator circuit is faulty (Abnormalities are detected when motor relay circuit is open/shorted or relay monitor circuit is open/shorted.)
Check the following:
Actuator motor, actuator motor arm position sensing switch and their associated circuits, TF-114, TF-115 and
TF-94.
The transfer case section of the service manual for a 2001.5 QX4 can be downloaded here: http://www.nicoclub.com/FSM/QX4/2001.5_QX4/tf.pdf
Or do you have a 1999?
I don't see a method for self-diagnosis without using Nissan's proprietary CONSULTII hardware in the 1999 shop manual. In any case, here is a link to the 1999 shop manual, transfer case: http://www.nicoclub.com/FSM/QX4/1999/TF.pdf
The ATX transfer case is difficult enough that Haynes refuses to publish any help for it. That said, you at least have some info to arm yourself with when stepping foot in the shop. Good luck.
Re: ATP Light, 4LO light flashing, and can't shift into Gear
Yes. 21 flashes points to the actuator motor/arm position sensor. The 1999 has a diagnostic. It's actually on the link you posted above.
Do you know anything about that particular part?
I'd prefer to try and fix it myself, but I can't find where to find the actuator and check it- if it's even possible to get to it.
Do you know anything about that particular part?
I'd prefer to try and fix it myself, but I can't find where to find the actuator and check it- if it's even possible to get to it.
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rgk
- Posts: 588
- Joined: Tue Dec 23, 2014 4:48 am
- Car: 02 Pathfinder LE 3.5 auto 4x4
- Location: Indiana Dunes National Park
Re: ATP Light, 4LO light flashing, and can't shift into Gear
I don't know anything about that part.
However, since you should have the same transfer case as a 2001, I looked again at the 2001.5 service manual and on pages 94, 114 and 115 it says to check the TF switch assembly sub-harness, transfer terminal cord assembly sub-harness connector, the transfer shift relay, actuator and actuator position switch, as well as the shift actuator circuit. It also lists resistances, etc., for these items.
It doesn't say on these pages where these items are located, but it might say so somewhere else in the manual. I would start with the relay, as it may be under the hood, and is probably the most likely thing to go.
If the 2001.5 manual is way off, I'd say it's time to hit the book and study the 1999 TF hard.
However, since you should have the same transfer case as a 2001, I looked again at the 2001.5 service manual and on pages 94, 114 and 115 it says to check the TF switch assembly sub-harness, transfer terminal cord assembly sub-harness connector, the transfer shift relay, actuator and actuator position switch, as well as the shift actuator circuit. It also lists resistances, etc., for these items.
It doesn't say on these pages where these items are located, but it might say so somewhere else in the manual. I would start with the relay, as it may be under the hood, and is probably the most likely thing to go.
If the 2001.5 manual is way off, I'd say it's time to hit the book and study the 1999 TF hard.