Newbie Qx4 questions

[Randy K]

Hey guys, new to the forum. I've belonged to a couple mustang forums and found them to be extremely helpful, hopefully I can find some help here too. I looked through a couple pages here and didn't see me problems so I'll ask a couple in one post. First my 4WD light comes on occasionally for no apparent reason, if I turn the car off and then back on it's out. Can I pull codes for this? If so, how do I do it on this truck? Also my ABS light will light up, but if it's cold out sometimes it will be out. That leads me to believe it's a loose connection somewhere. Any advice on finding that? Also where would someone suggest me to look for a leather bottom seat for the drivers side? Sorry all the questions in one post. Any help would be appreciated. Thanks in advance.
Randy

[Towncivilian]

Welcome to NICO.

See page TF-28 of the factory service manual for instructions on how to pull codes for the 4WD system.

And BR-42 of the FSM describes the ABS self-diagnosis procedure.

The junkyard would probably be the best bet for a leather bottom seat; if the dealer sells the part, it is likely exorbitantly expensive.

[Randy K]

Thanks Towncivilian for the links, and yes 563.00 at the dealer!

[Buzzman]

Can I pull codes for this? If so, how do I do it on this truck? Also my ABS light will light up, but if it's cold out sometimes it will be out.

Welcome aboard.
As for pulling codes, I would suggest investing in an OBDII code reader.
Doesn't have to be a top of the line unit. Just something you can pull the codes with and do a reset.
I bought one a few years ago and it has paid for itself 10 times over.
As for the ABS light coming on, most of the time it's nothing more than low brake fluid. Check it and top it up if necessary.
Cheers.

[Randy K]

Thanks Buzzman, I think I'll invest in one. Used to get away with an old analog multimeter on the mustang. As on the brakes, I've changed the front a couple times and keep an eye on the fluid level. That doesn't seem to be the cause. I'd hate to take it to the dealer and pay for them to chase it down.

[Buzzman]

I'm going to assume that the ABS doesn't work anymore?
Try jamming on the brakes on a wet road (or gravel road) and see if the ABS activates.
(Doing that on a dry road might stress the brakes a little too much).
If it's not brake fluid, then it's probably a dirty or bad ABS sensor.
If you've done the fronts, then you should be familiar with the ABS set up.
Keep us posted.

[Towncivilian]

The ABS self-diagnosis procedure should spit out a code telling you what exactly is causing the ABS light to be on. I'd try that first to see what we're up against.

[Buzzman]

The ABS self-diagnosis procedure should spit out a code telling you what exactly is causing the ABS light to be on.

Ah, that's too easy.
It's much more fun driving the crap out of your truck and then jamming on the brakes.....

[Randy K]

Hey Guys,
Did the 4WD self test and got: TF-65- 4wd shift switch circuit is shorted, and TF-75- ABS operational switch is shorted. Haven't done the abs self test yet maybe that will give me something else. Been working since I posted haven't had time to do the electrical test the service manual says yet. Hate electrical problems. More of a wrench kinda guy, but that being said, took me 20 mins just to change the drivers side headlight bulb the other day. Much different than working on my fox body mustang! Thanks for the help, and I'll let you know what else I find.

[mp66226]

I'm a QX4 newbie myself, just got an 01 with 125K on it this weekend. As such, I'm not sure about this model but I had a 03 I35 (maxima) and had the ABS light come on. Turned out it was one of the ABS sensors on one of the wheels. Looked just fine but changed it out and all was well. The code told which wheel too as I recall...? Or maybe someone on the forum suggested the one that failed most often. Can't recall for sure. Of course it was the most expensive of the 4 sensors...! Hope this helps.

[Randy K]

Ok been a little busy with work and all, I think they're trying to kill me! Anyway got a code reader and didn't get any codes on the abs, or maybe I'm just doing it wrong. But I did run engine codes and got 2 O2's bad, no big deal I can handle that, but I also got "intake valve timing control position sensor (left bank)". Is this a major problem? Doesn't sound good. I did get codes running the self test on the abs: 21, 25, and 31. 3 out of 4 sensors are open circuits, and it only holds 3 codes I think. I know I could read through the pdf file, but maybe somebody could tell me quicker if there's something that they all have in common that would cause that reading? Thanks in advance for any help guys.

[Towncivilian]

A generic ODB-II code reader will not read ABS codes, unfortunately.

What is the code for "intake valve timing control position sensor (left bank)"? P1140?

Have you ever flushed the brake fluid?

[Randy K]

Ok I bought the cheaper one so that must be it. Yes that's the code I got. And I bled the fronts till the color was good, but haven't flushed it thru the rears.

[suzook]

Even the best obd-II reader won't read the abs code...the abs system is not part of the obd system. More than likely you have one or more abs sensors bad. This in turn will also cause the 4wd light to go on. Currently I have 3 bad abs sensors. My 4wd light comes on also. Even with the 4wd light on, it still engages and works. Unfortunately the abs sensors are stupid expensive, and also rust in making them a pita to get out. Good luck.

[Randy K]

Wow suzook, just looked it up. Over $1k to replace all 4. I'm assuming if it is the sensors, if I read 3 bad, all 4 are probably bad. Was hoping they ran thru a common relay that would read open for all if it went bad. My 4wd also still works, was just envisioning my transfer case throwing shrapnel all over the place. Like when I'm 500 miles from home. Towncivilian, I'm impressed that you know that code from memory.

[Towncivilian]

You should flush in the proper order:

1. LSV air bleeder (4WD models only)
2. Left rear brake
3. Right rear brake
4. Left front brake
5. Right front brake

You can check the resistance of each wheel sensor to ensure it's within spec, see BR-59. Have you also checked the wiring on both the sensor ends and the ABS unit? BR-34 shows the position of the ABS unit.

For P1140, swap the camshaft position sensors between the driver and passenger side. If the code becomes P1145, the sensor is bad and should be replaced. I replaced both of mine with Standard Motor Products SENSORS from Amazon a few years ago and they have been fine since.

[Randy K]

I really appreciate your time and all the info Town. No I haven't really checked any connections or anything, didn't really know where to start. Glad I found this board, thanks again for pointing me in the right direction! It's going to take me a bit to get to it with my schedule right now, but at least I now have the steps to start taking.

[mp66226]

Did you check ebay on the sensors. While expensive, I would be surprised if they are that high if you can do it yourself. Seems like the abs sensors on my I35 were between $50-180 on ebay, each being a different price. Haven't looked though for the QX4.

[Randy K]

Ok, my fusable links are good, the sensors all read good at the wheel and through the harness. So I'm trying to read up on the next step. Hopefully it's not the actuator and electrical unit itself.

[Randy K]

Oh, and 16, 20 and 30 through the harness are o ohms to ground, which is correct. And I re-read the sensors and harness, and I'm getting 1.6k ohms through all of them. spec is .9-1.1k front and 1.44-1.76 rear. the fronts are out of spec, but it may be the cheap ohm meter I have. But the rears are within spec but also reading open on self test.

[Randy K]

Ok, hate to keep wearing out this thread, but... Put everything back together, cleared codes and drove it for about 15 miles. Tested the abs while I was out and it is working now. Wasn't before. No light or error codes came back up either. Maybe cleaning the connections fixed it. Fingers crossed. Now on the O2's and the intake valve timing control position sensor. Did I mention I have 195k on it. It's an unbelievably reliable truck. Best car I've ever owned. Wished they still made it, would buy another one tomorrow if they did.

[Randy K]

I was wrong. Back on this morning. Haven't had chance to run self test again. Crap!

[jbh]

help! p1145 is code coming up, replaced sensor cleared code and drove - all looked good, upon restart light on = p1145 swapped left to rt and code p1140 . switched back and p1145. bought another sensor clear code light stays off until restart then code p1145 rears its ugly head again, sensors i bought are non nissan what can cause this situation?

[Chuck Tribolet]

Which sensor did you replace? P1145 is left side, Bank 2, US Driver's side. The fact that the bug changed to
P1140 (which is right side, Bank 1, US Passenger's side) when you swapped sensors says that you really have a bad sensor.

Chuck.

[falcon007]

Im a newbie to this forum stuff so let me start by saying im an owner of a 01 infiniti qx4 I recently noticed that the engine light came on so I checked with my scanner or computer reader however u wanna call it n it said primary ignition signal so I searched the meaning of that online n it said that it was the coils so I changed all six of them including the spark plugs n I reset the computer n within 30 min the light came back on so checked again with the scanner n it said the same thing can any1 tell me beside the coils what's the usual problem with this type of car btw it has 77000 or if there's a sensor I need to change? Thanks

[asnorton44]

help! p1145 is code coming up, replaced sensor cleared code and drove - all looked good, upon restart light on = p1145 swapped left to rt and code p1140 . switched back and p1145. bought another sensor clear code light stays off until restart then code p1145 rears its ugly head again, sensors i bought are non nissan what can cause this situation?

You may have to drive a while for it to really clear; also make sure your not due for an oil change.

[Randy K]

ok just an update on the brake issue. I swapped the front left with a good one. Still gives me the open code after clearing the codes and driving a few days, clearing again and driving awhile them still get it. On the mornings lately that have been in the teens or lower, I don't get the light, but later in the day when it gets up into the 30's or so, it comes back. All this leads me to guess a short in the actuator/control unit. I'm not spending $1200+ to replace that. So my new question is, will this do any permanent harm to the truck to continue driving it like this?

[falcon007]

So can I get an answer to my previous question ur help will b really helpful. ..

[Towncivilian]

So can I get an answer to my previous question ur help will b really helpful. ..

Have you tried cleaning the MAF sensor? Re-tightening engine ground screws (see the general info thread linked in my signature for their location)?

@Randy K: have you measured the resistance of the ABS sensor when it's warmer out? Perhaps the resistance is out of spec when it's not cold enough. If it checks out fine, then I might suspect the wiring or ABS control unit. You also haven't answered my inquiry about the brake fluid, has it been flushed within the past two years?

[Randy K]

Hey Town, Yes I've measured when it was warm and bought a new one anyway and still get the same code from the same wheel. I've also measured the harness, the shop manual doesn't say how to sheck the actuator, it just says if everything else checks out, replace that. And no I haven't flushed the brake fluid. I didn't think that would upset the readings, but I will do that next chance I get. That's the last thing to try for me I guess. Thanks for the suggestion.