CEL Limp mode help (1 Viewer)

[LoveMyLX]

Hello all,
So this morning my 2000 LX470 check engine light came on but I was able to drive it for 2 miles to the train station without a problem. Then afterwork I got in, started the car right away and the CEL still remained on. Well, I needed to get home so I started driving and my truck would only go about 2-4 mph despite how much I stepped on the gas. So I turned on the hazards and "limped" home. I must say that was the longest 2 mile drive home I ever had..haha.

I eventually made it home and checked the car with a OBD II tool and only got this code P0110 which said "Intake Air Temperature Circuit" malfunction.

So my question is, what steps should I take now? I did some searching and I guess my first order of operation is to clean the MAF sensor with CRC MAF cleaner or I also heard that I can pick up from Radio Shack a can of electronic circuit board cleaner and use that too?

If anyone else has some other suggestions I would most appreciate it.

Thanks!

 

[Layonnn]

Sounds about like what i would do as well. I would get the CRC stuff just to make sure you buy the right can.

When you pull the MAF i would disconnect the battery before you spray it down with the cleaner. The sensors are little resistor looking devices. Make sure that they are not damaged.

FWIW, i usually clean my MAF every time i replace the air filter, or about every 15K miles. The wires start to get dirt build up and i usually pick up a MPG and better throttle response if its been a while since i cleaned it.

 

[rusty_tlc]

When you disconnect the battery it will also clear the code right?

 

[LoveMyLX]

Thanks for the confirmation Layonnn!

Also, like rusty_tlc mentioned, if I disconnect the battery, will it clear the code or will I have to use the OBD tool to clear it?

 

[Layonnn]

When you disconnect the battery it will also clear the code right?

Depends. Some codes can clear by unplugging the battery, some will stay on.

If its an on going problem, the light will usually stay on or come back on shortly after re-connecting the battery. The same thing applies to an OBD2 scanner/code reader as well.

For example, say you have a bad 02 sensor. You can clear the code with the scanner, it will just show right up again until you fix the problem. However, after you fix it, you may need the code reader in order to get rid of the CEL still, but it should stay off after that. I haven't had to do this much on my 100 but this was the case on my 80 and my FJC.

 

[LoveMyLX]

Update: so I pulled the MAF sensor and guess what I found, a dead spider that looked kinda squashed on the sensor. Anyway I spayed the heck out of the sensor with CRC MAF sensor cleaner and let it dry. Then plugged it back in and still no luck .

So my next step is going to replace the entire MAF sensor. I'll keep you guys posted if replacing the sensor does the trick.

 

[OregonLC]

Interesting. So does the 2000 LC and LX have different control logic? On my truck the pedal hits a soft stop at about 3/4 stroke. At that point the cable takes over and manually opens the throttle body (with increased resistance). While I've never unplugged the MAF, I have unplugged both the TPS and APPS and I can get near full power, albeit it with a decrease in modulation. I post this because this 'cable backup' IMO is a very compelling feature of the early LC's yet it seems to remain unused (unknown?). I'd hate to see a fellow 100 owner get stranded while the capability remained unused. Perhaps the cable is poorly adjusted and there's too much slack to get it into manual mode?

That said, I'll need to try unplugging the MAF to verify it still works. I can't imagine not as the ECU will have to react to the increase in throttle angle. I'm betting there's a backup map in the ECU that provides a fuel curve based upon that and short fuel trim from the primary O2's.

 

[Layonnn]

Update: so I pulled the MAF sensor and guess what I found, a dead spider that looked kinda squashed on the sensor. Anyway I spayed the heck out of the sensor with CRC MAF sensor cleaner and let it dry. Then plugged it back in and still no luck .

So my next step is going to replace the entire MAF sensor. I'll keep you guys posted if replacing the sensor does the trick.

Hmm, maybe it messed up something? Do you know anyone in your area with a 100/470 so you could borrow their MAF? This would save you the large price tag of getting a new one (especially if that didn't fix the problem). I'd try to find a low mileage junk yard replacement. MAFs are pretty pricey.

 

[LoveMyLX]

Update 2:

So I got a new Mass Airflow Sensor and proceeded to do the following:

1. disconnect the battery
2. replace the MAF sensor
3. wait 15 mins with the battery disconnected
4. reconnected the battery
5. turned on the car

Result:

The check engine light still remains lit.
So anyways, I take the car for a spin and drive around the block and step on the gas. The car seems to respond to the gas pedal normally now, no limp mode, but then why is the check engine light still on???

Do you guys think I need to drive the car for a little longer on the road to see if the CEL goes out versus just driving around the block?

I even then tried the OBD tool to clear the code, but the CEL still remains lit and the same code comes up: P0110. sigh.

Any thoughts anyone?

Thanks!

 

[Brock]

it needs to be cleared....some you can clear with an UltraGuage/ScanGuage while others need a shop to clear if they do not clear themselves. Have them read to see if same code is being thrown...if cleared and it comes back then there is another issue. If cleared and stays gone then that fixed it for you.

 

[LoveMyLX]

it needs to be cleared....some you can clear with an UltraGuage/ScanGuage while others need a shop to clear if they do not clear themselves. Have them read to see if same code is being thrown...if cleared and it comes back then there is another issue. If cleared and stays gone then that fixed it for you.

Is an UltraGuage/ScanGuage different than using the OBD II tool that I borrowed from Autozone?

Actron/OBD II Autoscanner plus tool for 1996 and newer vehicles, bilingual (CP9180) | Code Reader | AutoZone.com

Thanks!

 

[LoveMyLX]

Hmm, I also read somewhere that I can reset my ECU by pulling and reseating the fuse to the ECU or ECM? Has anyone heard of that method?

 

[hoser]

Do you guys think I need to drive the car for a little longer on the road to see if the CEL goes out versus just driving around the block?

I even then tried the OBD tool to clear the code, but the CEL still remains lit and the same code comes up: P0110. sigh.

If the problem is corrected, the CEL will normally turn off on it's own but could take up to 50 miles including freeway time. If the problem persists, you should be able to clear the code and then the code will pop up within a number of miles.

It sounds like you may not be clearing the codes correctly?

 

[LoveMyLX]

Update: So I finally drove about 20 local miles and the check engine light went off!
Woohoo!

Thanks everyone for your help and input, it was all greatly appreciated.

Cheers!

 

[LoveMyLX]

Update:
So after a couple of days of troublefree driving, the check engine light lights up and once again my LX goes into limp mode...Arrgghhh! Time to goto Autozone again to borrow the OBD scanner again..sigh.

 

[LoveMyLX]

Got the odb scanner and got the code P0110. Hmm so I already replaced the mass air flow sensor. What else could it be? Thanks in advance for any ideas.

 

[geocruiser]

Got the odb scanner and got the code P0110. Hmm so I already replaced the mass air flow sensor. What else could it be? Thanks in advance for any ideas.

LoveMyLX, Any updates for us?

My LC had a very small "stumble" when taking off from a stop sign this morning. After about a 1 second shutter of the whole truck, it drove fine for the rest of the trip to the store and back home.

A couple hours later, I was leaving the house and the check engine/vsc/atrac lights came on. I pulled the codes P0100 & P0110 with my OBD2 reader/Torque app.

Did you find the issue to your problem besides replacing the MAF sensor?

 

[LoveMyLX]

LoveMyLX, Any updates for us?

My LC had a very small "stumble" when taking off from a stop sign this morning. After about a 1 second shutter of the whole truck, it drove fine for the rest of the trip to the store and back home.

A couple hours later, I was leaving the house and the check engine/vsc/atrac lights came on. I pulled the codes P0100 & P0110 with my OBD2 reader/Torque app.

Did you find the issue to your problem besides replacing the MAF sensor?

Hi geocruiser,
After I was about to give up, it reseated my MAF and in addition i pushed the wires that go into the MAF connector a little harder and it worked! I guess when i replaced the MAF sensor I must have shooked the wires loose a bit. But after I push them in hard, the CEL lights eventually came off. I hope your issue will be solved just as easily.

 

[geocruiser]

Hi geocruiser,
After I was about to give up, it reseated my MAF and in addition i pushed the wires that go into the MAF connector a little harder and it worked! I guess when i replaced the MAF sensor I must have shooked the wires loose a bit. But after I push them in hard, the CEL lights eventually came off. I hope your issue will be solved just as easily.

That's good to hear.

I had my airbox apart when I installed my snorkle about 2 months ago, and cleaned the TB and MAF while I was there. Maybe I didn't put the wire harness back on properly. I'll check that our first.

Thanks!

 

[geocruiser]

I cleaned the MAF sensor with some CRC MAF Sensor cleaner, and drove the truck to work today to see how she acts.

All was good on the way to work, and 90% of the way home (33 miles on-way), and then it happened again : pulling into the intersection after being stopped at a red light; hit the gas, truck shutters, and this time I look down in time to see the a-trac light is on... confirming that it is the atrac kicking in when I hit the gas (the shuttering mentioned in earlier post). I'm assuming this happened the first time last Sunday, but I did not notice the light. It also felt like it was only the front wheels doing this, but I am not certain.

The same check engine/abs/vsc lights were lit on the dash until I pulled into a parking log and shut the truck off. Started it back up, lights are off - no error codes were stored this time!?! (had my bluetooth dongle and torque app-equiped phone). Drove fine the rest of the way home.

A new MAF sensor will be here next week. So she will sit in my driveway until then. Hopefully that will fix the problem!