AJT

Quick background,

Just bought an 05 TL (automatic) last weekend. ~83k miles at the time. Picked it up in Houston, TX and drove it back home (near Little Rock, AR). Nearing the end of the drive home, we were on the highway, doing about 75 with the cruise on, when alll of a sudden the cruise kicked off and simultaneously the CEL, VSA light and triangle with an exclamation point light (sorry, dont' have the manual in front of me) went on. The car still had power fine, but wouldn't go back into cruise.

We exited at the next available exit, and after stopping at the off ramp to turn, the car had very little power, wouldn't really accellerate past ~20mph as if it were being limited. We pulled into a gas station, filled up, looked around a bit but couldn't find anything.

When I turned the car back on, the car was back to normal other than the CEL staying on. It drove fine the rest of the way home, cruise worked, etc. I did some reading on here that night about the APP sensor and it seemed to fit. The next day I started the car and the CEL was off, but took it to Autozone and got the code read. It was the 'TPS Sensor'. Sorry, I didn't write down the P code, as I just thought I had confirmed my assumption. The guy cleared the code for me. I ordered the APP sensor and it showed up on Thursday.

I installed the new APP sensor yesterday, although I hadn't had the problem again since last Saturday on the drive home with the car and had put around 700 miles on it since then.

On the way into the office this morning, was cruising on the highway around 60 mph when the exact same thing happened. Cruise control kicked off, the three lights went on. The car still had power fine on the highway. I found a side road just down the way and slowed down and turned on to it. Sure enough, it felt like I was speed limited to around ~20 mph. I pulled over, shut the car off, turned it back on, and the CEL was still on but everything else was fine. Made it the rest of the trip in to work with no issues.

So, the reading I did on hear indicated to me it was the APP sensor, but I just installed a brand new one yesterday and this happened today? I didn't unhook the battery or anything when I swapped it out, but it doesn't seem that I should have had to?

Any and all help is greatly appreciated! BTW, love the car!

CometVR4

First thing to do is get the CEL code and post it here.

I hate cars

An easy start is to check the wiring and connections. Make sure all pins look good and tight and are free of water and oil. I'm not sure of the requirements to set the code but you could also have a bad ground and believe it or not the battery and connections can cause all sorts of weird things to happen. Just a few free things to look at before you throw more money at it.

Does this only start happening when it's on cruise?

AJT

To answer the questions above and provide a brief update:

I had the code scanned again, it came out P0122 (same as last time now that I recall). The CEL had gone out, but the code was stored. The guy cleared the code for me.

On the drive home, it did it again. All three times it's been while the cruise control was set (though in fairness, probably 90% of the miles I've put on the car have been with the cruise set as I have a lengthy commute to and from work). This time, I played with it a bit to see what else I could learn. It maintained power on the highway, but I laid into the gas a bit and it wouldn't downshift. I pulled off to a side road and put it in the 'manual' mode, and it was in '2' and wouldn't allow me to up or downshift from there. I pulled off the road and it remained in '2'. I put it in reverse and reverse worked fine. Put in park, then back in drive, and it still seemed limited in power (may be that it's trying to start in 2nd gear). Turn the car off and back on, and it's like nothing happened, other than the CEL remains on.

AJT

I tried my luck at justanswer.com

The claimed many year Honda Tech said that the P0122 usually requires replacement of the entire throttle body. He also said that it happens when the A/C drain line clogs and leaks on the ECU, effectively burning it up. He told me to inspect the ECU for any signs of water, which I did, but nothing. I'm reluctant to replace the TB without some supporting information. I've googled as much as I can but haven't been able to find any supporting information.

AJT

So I gave up and took it to Honda (the nearest Acura dealer is about an hour from where I work). Turns out there was a dead cell in the battery that was causing voltage irregularities and hence the issue. New battery, no more problems. Me being new to the car, I didn't know what to expect as far as how quickly the starter spins, etc. Never really noticed any lights dimming or anything, but there you go.

I hate cars

That's why I mentioned the battery. It seems like if the starter starts the car ok it would have more than enough to power the electronics. But I had to learn the hard way that it can be intermittent, start the car fine but cause weird problems with the electronics. Were you able to get a refund on the sensor?

AJT

Thought I'd provide a (belated) follow up in case anyone has a similar issue and searches. The problem re-occurred within a day or two of the battery being replaced, throwing the same code. I ordered a new TB/TPS from acuraoemparts.com and replaced it myself when it arrived a few days later. Since then, no issues, and I've driven it a good 5k+miles since then.

I was too presumptuous with the APP sensor, so there's a ~$100 lesson learned, but I'd have needed a battery regardless.

The other thing I wanted to say is how much I appreciate this site. I've found some great technical knowledge when I've searched other small issues that have saved me a ton of money. I've spent plenty of time on other car boards and this one really does well.

Anyway, that's my story.

NE14RoxCJ

Only happening with the cruise set would mean the APP sensor is out of the circuit. That is just for the Accelerator Pedal Position. I'm sure you've thought about all that now. Oh well. That APP sensor was liable to fail soon anyway (trying to mke you feel better.) Good job on the fix and welcome to TL ownership. We're probably close by. I'm in Benton. I drive my '04 to Little Rock daily. I also bought my TL from TX (Dallas area). And I also had an APP sensor go bad. Although yours ended up being the TB. Glad mine was the cheaper fix. Mine never really "failed" though. Just acted funny out on the highway. Good luck with your car and remember this site. It is full of any information you could ever need.

Greg D

I had the exact same problem with my car, except it happened without using the cruise control. Same code, same symptoms. VSA and Check engine ligts pop up, then the car goes into limp mode. They replaced my entire throttle body first, which didnt correct the problem. Then they replaced my APP, and that ended up being the fix.

NE14RoxCJ

I hope that was warranty work. Those parts are expensive. Hopefully a few of these threads will help people to troubleshoot the problem down to the right part.

It seems like if the problem occurs with the cruise control, it tends to be the Throttle Body. If it only happens when using the pedal, but not with cruise, it's likely the APP sensor. The throttle body is the common piece. That electric motor can be controlled by either the APP sensor (gas pedal) or the cruise control module. Maybe this will save someone some money one day.