Bad PCM - Car in Limp Mode - Safe to Drive?


#1

My check engine light went on and I took it to the shop and the mechanic said it was a problem with the computer, bad pcm, and that it needed to be replaced and reprogrammed (cost more then 1K). They said it’s not sensing power from the fuse block, error codes P0700 and P0822 for a 2006 Pt Cruiser. Now it’s in limp mode and I was wondering if it’s okay to drive if I stay below 40. I don’t have the money right now, and I work graveyard so it’s not really possible for me to take the bus, so I’m wondering if it’s okay to just take it to work if I stay below 40. The car has had a number of problems and I’m just going to junk it, but wondering if it can last a few more weeks, at least until Dec 1st.

Thanks-


#2

I have never had a car go into limp mode, but my recollection is that in limp mode, the trans will not shift up beyond second gear. Assuming this to be correct, I think that 40 mph would really be “pushing it” with your ailing transmission, because 40 mph in second gear will have the engine turning at pretty high RPMs.
If my vehicle was in “limp mode” I would try to not take it over 30 mph, and I would be driving it immediately to a competent mechanic’s shop.


#3

Not really any of my business but if you are junking this vehicle what does Dec. 1 have to do with replacing it . That is only a month away , you can have many vehicle loans start the first payment 60 days from purchase time.


#4

Yeah agree. Our Olds was the only car that went into limp mode and that was stuck in 2nd gear. 40 would be a little high for 2nd gear. But what the hey, you’re going to junk it anyway in a couple weeks so what does it matter. I would just speed up your time table instead.


#5

Get a new mechanic. Those are transmission codes. P0700 is a generic “there’s a transmission problem” and P0822 is a gear position error. Both could be caused by faulty electrical connection to the transmission solenoids and sensors, or a faulty sensor or solenoid. Fairly common failures in these transmissions.


#6

Thanks for the replies.

It was P0882 not P0822.Mechanic said it read TCM Power input low, and recommend replace PCM (not sensing power from fuse block). And they said it couldn’t just be refurbished but had to be a brand new one that is reprogrammed too.

The car in limp mode can go up to about 45, after that it starts to go past 5 - RPM. I live on the same street where I work and it’s just a straight shot, down a 40mph road, so thats why I’m wondering about that specifically.

About the car loan, I’m a student and my credit and income aren’t great so I don’t know that I’d get a decent loan. I’m waiting for Dec 1st because right now work is slow. but it supposed to pick up soon, so I should be able to make more money to hopefully put a down payment on a car around then.


#7

I definitely suggest a second opinion. It could be a $50 sensor and you would be good to go. Do some of your own research to save money. If you spend a few bucks and fix this you might be able to keep it a little longer and put more money aside. This is what I would do.

You are probably OK to limp this along for a month, especially if you plan to sell it at junk value. You will burn more fuel in limp mode but it should work.


#8

I would get a second opinion as well, as this sounds more like a wiring or sensor issue than a bad PCM. Also, even if the PCM truly is the problem, which I don’t believe, you could actually buy one online programmed to your VIN and option level for a LOT less than $1000 and install it yourself.

That being said, if the car is in very poor condition, and you’re going to junk it anyways, then of COURSE you should keep driving it until it dies–not just until December 1. As long as you check the oil frequently and add/change as needed, the car could likely be nursed along for a lot longer than a month–basically until the transmission gives out completely, or you need to pass an emissions test again.


#9

P0882 is still unlikely to be the result of a bad PCM. Read here: https://www.troublecodes.net/pcodes/p0882/

The TIPM under the hood is more likely to be the problem than the PCM, but a wiring fault is still the most likely cause. I stand by my earlier advice: find another mechanic.Your current one doesn’t seem to be interested in doing rigorous diagnosis.

Were the codes cleared? Electrical gremlins can sometimes pop up, never to reappear. Not likely, but it’s worth a shot. An inexpensive code reader may be able clear them.


#10

Make sure all the grounding points are good under the hood. I have seen grounds for sensors cause all kinds of odd things to happen.


#11

The P0882 code is most likely happening because there is simply a bad wire connection somewhere in that circuit. Find out where the power comes from that provides power to the TCM and check the power there. It will most likely be okay at the starting point, if that is the case then the problem connection is further down the line, before the connection at theTCM.


#12

I looked online and the p0882 seems to be common with 2006 pt cruisers. But it seems like everyone who experienced this said it was because of a different explanation.

This site says its a failed tipm and wiring issue:

This site says one person it was the ground wire connected to the battery, another says it’s the radiator hose, another bad tipm, another says it’s a connector issue and had to print out a diagram for the mechanic to find the problem.
http://www.ptcruiserlinks.com/forum/tech-performance-forum/37700-p0882-low-input-signal.html

And then youtube had a guy say it’s either the tipm or pcm, but said you could replace it if you just buy it used, but then the mechanic who said it was a bad pcm initially said I couldn’t specifically do that, it had to be new.

If I just take it to another mechanic to diagnosis, are they going to actually be able to diagnosis it or are they just going to tell me the same thing the mechanic did? Is there a way to know before hand if they do a proper diagnosis or am I just taking another crap shoot with mechanics?

If the mechanics are just guessing I’m tempted to just buy a used tipm and try and replace it out myself, but don’t want to do any permanent damage to the computer.


#13

You said you were going to junk this thing. If it will get you to work and back why spend any money on it which you say you do not have. Do you not have any relatives that can help or loan you a vehicle for a short time ?
Just throwing parts at a problem is not a good idea.


#14

Finding the cause of the error code P0882 should be a pretty simple task for a good tech. It is most likely due to just a bad wire connection. No radiator hoses are involved.