I replaced the MAF for the 3rd time about 8K ago. She has almost 130K on her. 3 days back the SES came on. Limp mode kicked-in. Next day took her for a ride. SES was still on, but limp mode was gone. Took her to autozone and got the dreaded p100 code. Had an extra maf laying around and switched it. Cleared the SES, car drove fine for 30 minutes, and limp mode kicked-in again. Left work 10 hours later. SES gone, and she was driving fine. Redlined her twice, and about 30 minutes later SES came back along with limp mode.

Any ideas???


Seems like limp mode and ses come after driving for about 30 minutes. Let her sit for a few minutes and limp mode is gone. But then it comes back..

 

tonight, i think i had the same issue. i dunno what exactly limp mode means, but my car felt like it wasn't drivable! surging/pinging/hesitation put together, but overall it felt like a wheel bearing issue gone bad to it's extent. i put it past 3k and BAM! SES LIGHT BLINKS (it was on prior due to o2 sensor)... i'm thinking WTF... i can barely drive because the car just feels like i'm going over lump after lumps in the road. finally i get a mile from my home and then no more bouncy ride. i'm gonna clean my MAF tomorrow and let you know how that goes.

can we share this thread lol... we are on the same page

 

limp mode is severe hesitation and the car will not go over 2500 rpm...

 

exactly what i experienced tonight... only time i tried going over 3k was 3rd gear, every other gear felt like the car was going to fall apart after 2k

 

Inspect the wireing going into the MAF- the connector itself. Jiggle the wireing while the car is OUT of limp mode and see what it does. Its a common problem on the G50 series Q45 that the wireing to the MAF crapz out, might be similar to the A33.

 

That's a coil issue not the MAF.

 

i do know my MAF is bad and i was thinking it's just getting worse and worse when this occured. i'll check autozone tomorrow, but for now my batt is unplugged for the night...

 

Mike,

I was actually thinking that there is a vacum leak?? I will check the wires tomorrow..

 

Yeah, that's what I was going to say. Sounds like something just isn't tight. Check all of the wires, plugs, hoses, etc.

And just to be on the safe side, give your throttle body a glance too.

 

for vacum leaks, which hoses need checked?
thanks

 

Vacuum leak isn't going to set off a MAF circuit code. That code only comes up when the MAF or the wireing to it is bad. You could test the wires by ohming out the connector at the MAF and the ECU to see if there is too much resistance in the wires- too much means its eighter deterriorated wireing or broken wire somewhere.

Per FSM, pinch the PCV hose and see if the RPMs climb up or stay even, if they climb up then you have a vacuum leak- which will not be an issue with your problem.

Check the wireing, and MAF connector for corrossion, possibly spray the connector down with some electronic parts cleaner, and then put in some dielectric grease in the connector to seal it from any type of corrosion forming on the contact points inside the MAF connector and the MAF itself.

 

per FSM


though it would have to be a pretty big leak.


how do you know the used MAF is good? id ck it installed in another maxima and see what you find

 

thanks for the replies. i have ordered a new maf just to make sure. ses is still on. i have not tested the wires by ohming out the connector to the maf and ecu. frankly i don't know how to do that..we'll see after the new maf..

 

Hope you get this problem fixed, Jay.

 

i tried what mike suggested, and so far it has fixed the problem (thanks mike). i will post on monday, after i drive her to work...

 

If you had a large enough vacuum leak it would set off a system to lean code 1st before MAF code. Looking at the consult Alpha would be way off.

Zippn- what did you end up doing ? clean up the MAF connector ?

 

I cleaned the connector like 5 times with the electronic parts cleaner. I am getting ready to go run some errands. I will probably drive like a 100 miles. With that many miles, I am sure I will find out if cleaning the connector fixed the problem. Will post results after the drive..

 

not quite... the STFT would run lean first, and then then LTFT. if the LTFT isnt out of threshold it wont throw the fault, but if theres insuficient flow across the sensor, the ECM will call it dead in the water with a p0100, and mixture diagnosis gets thrown out the window at that point, going into FMEM.


meh... either way, its not likely, hed have other symptoms and with the way MAFs go on these cars, i doubt its a vacuum leak, but i wouldnt discount it without taking a good look...

 

I'm going off Alpha on the Consult, which will tell you alot more than normal STFT and LTFT. Its read in % and gives you a better idea of how the car is runing. I hardly use fuel trims on Nissan or Honda, since on a Honda you can see the actual A/F reading, and how much more or less fuel is dumped into the engine via injector duty cycle. Most newer Japanesse cars have wideband lambda sensors which display true A/F ratio using a manufacturer supplied scan tool. They call nolonger call oxygen sensor an oxygen sensor, but A/F sensor. Its able to fine-tune the engine to specific gasoline used in the engine, diff ambient, engine load and intake air charge better than old school O2 sensors.

P0100 is a MAF circuit maulfunction, which pretty much eliminates everything but the electrical parts of that system. If I where to remove my brake booster hose for long enough of a time, it will register a code for system lean- not a MAF problem, even thou its a HUGE vacuum leak.

Nissan FI is pretty good stuff, its got alot of fail safe modes, and has REALLY good misfire detection built in, and if you got a Consult to access it makes fixing the car virtually all but impossible. Early 1990s cars had more sensor values shown and more adjustments you can do via Consult, or tests- than todays Honda cars.

 

I have driven her about 150 miles. No more SES. Installed back the maf I had when the light first came on. Redlined many times. She is back to purring...$7.00 bucks is all it cost. Thanks Mike

 

yes, as a Porsche master tech, im familiar with the operation of a wideband O2 sensor. besides a/f ratio doesnt tell you how far the figure has already been adjusted. trims work just fine... and if Alpha is anything like RKAT on a Motronic DME 8 then its based off of fuel trim anyway...

disconnect the intake tube at the t/b, start the engine and tell me what you find

hmm... makes me wanna take my 91 to the nissan dealer and talk to one of the techs

 

well..it's back. SES came back this afternoon. I was just cruising when it popped-up...I am kinda getting sick of this ****..

Mike, now where do I start..........

 

It comes and goes eh ? I have had good luck with the new updated MAFs from Nissan so far (knock on wood been ok for over 40k), so I would possibly rule out a bad MAF. I would check the wireing from the ECU to the MAF. Get a hold of a FSM and look at the circuit diagram for the MAF wireing from the ECU to the sensor. Possibly run a continuity check (ohm out) on the wireing. Check for short to ground also.

 

Hey fellas i got a 2000 Max with the same problem, this limp mode you call is what i been dealing with for a lil while. had it checked out said it was a coil problem need to replace all six. Even bigger problem is getting fixed so i can get the car inspected and get her back on the road. any info you guys can help me with i'd be grateful
-Po

 

if youve got a p1320, then its either a coil issue, and youll be replacing all 6, or a wiring issue... most likely the former... good luck.


zippin, you getting the same p0100?

 

Thanx for the info. i replaced all six coils........that was a fun time @ the checkout counter. getting the car back tom. hopefully i'll update on how its running for any who have had similar probs.

 

i worked on her yesterday. found a house was disconnted to the air intake. still don't understand why limp mode would kick in a few minutes into running

 

hey umm... didnt i say that?

because voltage doesnt come above threshold for a given RPM, and as soon as you get p0102, p0100, p1102, or p0101 (i think), you get FMEM. simple, really.

 

well i got the car back yesterday she was running like she used to. drove for about 60 miles then the SES came back on, had her plugged back to the comp. got a 430? which is a cadalic converter issue. sounds a lil off to me car only has 77K she shouldn't have issues like that. if any1 knows anything about a 430 the help would be sweet. thanx

 

p0430 is bk2 catalytic converter, IIRC theres also an ECM update for the problem.

its covered under 8/80 emissions warranty, go do the dealer on monday before you hit 80,000 miles.