[sccars49]

I have been chasing cause of a low idle misfire for couple years now. When under acceleration & @ cruising speeds the eng runs fine w/plenty of power. Mileage currently around 90k. Have done all checks for compression, leak down, cleaned upper intake manifold ea time removed, replaced plugs 2x w/correct plugs per decal under hood, plug wires, coil, crank sensor, cam sensor, had computer checked @ dler, who said was an injector problem, so replaced all 4 injectors, coolant sensor, timing belt(along with several items nearby), and nothing has improved anything, except last go around with removing & cleaning injectors seems to have made car idle faster(still missing when at low idle ), so now we have to hold brake down harder to keep it stopped. That may be a leak around seals but haven't located it yet if it is. Thought I would go ahead & replace computer( # 292AD) anyway so got an LKQ w/91 day warranty, Installed it but car would only start, run a second or 2 & die. I called LKQ supplier & was told I may have to have LKQ computer programmed by dlr to my veh to make it work. Is this true? I figured it should be simple plug in & go or the computer supplied is defective. I also noticed some reports to check the coolant fan 2 spd relay. I will do that also. Another possibility is wiring harness short but haven't found anything obvious yet. Anyone else have any more suggestions/solutions? But, first I need to resolve computer issues before warranty period runs out. Thanks.

 

[John Wood]

Most likely, the computer will have to be reprogrammed by the dealer because of the electronic security system.

 

[Russ67]

The service manual definitely says a new controller would have to be programmed by a dealer to set the vin number and mileage. Makes trouble shooting at home difficult.

 

[ImperialCrown]

If you have the gray SKIM key, the 4-digit key code has to be put in the PCM to validate the PCM. The dealer is the guy.
I'm not sure that the PCM is the problem with your idle misfire issue.

 

[Russ67]

Just curious, what did the new PCM cost? I suspect that I'll be buying one soon and want to be prepared for the worst. I don't know if anyone other than a dealer can re-program it, and also don't know if a dealer would even do it if I don't buy it from them.

 

[BarryFricks]

My 2006 PT started missing about 40,000 miles, it now has about 82,000 miles. The dealer replaced the cooling fan relay and also the fan itself and this solved the problem. It was rather expensive because the dealer said the fan and the relay were one unit that could not be separated but at least the missing was solved at it hasn't missed again.

 

[sccars49]

Thanks for info. I had gotten an LKQ PCM from local salvage dlr for $125. I have since been told by a local auto electric repair shop that he can reset the computer. I will do some more checking today on relay etc as mentioned above before taking it to him on Tuesday next week. Hopefully I can resolve it finally before going that route, although there are other issues from prior, ie the fog lamps no longer work(won't switch off unless horn fused pulled?) I did something a couple yrs ago when first occurred to allow horns to work w/fog lmps unplugged & still needs to be resolved. First things first. Get it running better today hopefully.

 

[ImperialCrown]

Multifunction switch was a problem for f/lamps staying on and discharging the battery. Improved switch in 2009. The plastic steering column halves separate to service the switch.