[Stylemaster47]

I ordered a rebuilt ECM from "Car Computer Exchange .Com" and installed it, and have driven about 150 miles and so far the dreaded P0031/P0037 codes have not returned!! YEA!! The ECM was $309 and that includes their 2 year warranty. I shipped my old one back to them.
Another happy Cruiser !!

 

[Jtweedie]

First, thanks to those who have posted on this problem; I was tearing my hair trying to nail it down! I have a '04 2.4 Turbo (low output) with the P0032 and 37 problem, and have gone through the same troubleshooting steps that are outlined in the previous posts, with a couple of twists. When I first began looking for the culprit I discovered oil in ECM connector cavity No. 2 (orange), which I guessed must have wicked up from a leaking sensor. I replaced the cam position sensor and power steering sensor, which were both leaking. However, the codes kept coming back and despite repeated cleanings with contact cleaner and sealing the wiring harness with silicone I kept finding oil residue inside the sealed connector. Finally concluding that since all other possible culprits had been eliminated I sprung for a "rebuilt" ECM from allcomputerresources.com. When installing the "rebuilt" unit I confirmed that no oil was coming through the wiring harness so it must have been coming from the ECM all along. After installing the ECM there were no codes and the car ran like new (it previously had an intermittent miss that would appear only after the car was driven, then parked for an hour or so). --For a whole day - about 20 miles of driving. Today, it quit entirely but I was eventually able to re-start it and nurse it home even though it was running very roughly and quit several times during the one-mile drive. I checked the codes and, surprise, no P0031 & 37, but just the opposite: P0032 & 38 (high heater voltage instead of low) - plus P0201, 202, & 203 (injector circuits). Obviously, this ECM is bad too, so it's back to allcomputerresources for a replacement. I'll report how it goes.

My wife loves her PT, and no new car suites her so I hope it can be fixed, and I hope that relating my experience will help someone else who feels the same.

Thanks again to all who have posted on this problem.

 

[Jtweedie]

First, thanks to those who have posted on this problem; I was tearing my hair trying to nail it down! I have a '04 2.4 Turbo (low output) with the P0032 and 37 problem, and have gone through the same troubleshooting steps that are outlined in the previous posts, with a couple of twists. When I first began looking for the culprit I discovered oil in ECM connector cavity No. 2 (orange), which I guessed must have wicked up from a leaking sensor. I replaced the cam position sensor and power steering sensor, which were both leaking. However, the codes kept coming back and despite repeated cleanings with contact cleaner and sealing the wiring harness with silicone I kept finding oil residue inside the sealed connector. Finally concluding that since all other possible culprits had been eliminated I sprung for a "rebuilt" ECM from allcomputerresources.com. When installing the "rebuilt" unit I confirmed that no oil was coming through the wiring harness so it must have been coming from the ECM all along. After installing the ECM there were no codes and the car ran like new (it previously had an intermittent miss that would appear only after the car was driven, then parked for an hour or so). --For a whole day - about 20 miles of driving. Today, it quit entirely but I was eventually able to re-start it and nurse it home even though it was running very roughly and quit several times during the one-mile drive. I checked the codes and, surprise, no P0031 & 37, but just the opposite: P0032 & 38 (high heater voltage instead of low) - plus P0201, 202, & 203 (injector circuits). Obviously, this ECM is bad too, so it's back to allcomputerresources for a replacement. I'll report how it goes.

My wife loves her PT, and no new car suites her so I hope it can be fixed, and I hope that relating my experience will help someone else who feels the same.

Thanks again to all who have posted on this problem.

 

[Jtweedie]

Just an update: after calling the vendor for the rebuilt ECM and reporting my experience with the unit they recommended resetting it to see if that would help before sending it back for a replacement or refund. After resetting it (remove negative battery cable, then remove all ECM connectors, wait 1 hour then reassemble in reverse order) no codes showed up, and I drove it for about 5 miles then parked for a couple of hours. Upon re-start the check engine light came on (codes P0032 and 38 again) and the engine quit cold. After finally getting it restarted it ran very roughly and died again in about 20 feet of driving. I hoped that if I re-set the ECM again I might be able to get the car home, but I got the same result. Fortunately I had the old ECM with me, and after installing it the car fired right up and I was able to make it back home. A check with the local Chrysler dealer revealed that they could supply me with a rebuilt unit for $634, or a new OEM unit for $865. Before spending that kind of money on a new unit I guess I'll tear the wiring harness apart to see if I missed anything the first time around, but I doubt it.

I'm still curious: has anyone else found oil residue in any of their ECM connectors? I haven't seen that mentioned in this thread.

 

[mr2tim]

Personally I'm seriously believing all these PT Cruiser's PCM's are a ton of crap. I'm listening to all these serious money losing "guess" swaps, severe money being sadly wasted and the bottom line seems to be this Chrysler part(s) is just junk waiting to fail. This thread being 2 years old is proof.
Don't get me started on a user UNFRIEDLY manual.

I have 425,000 miles on my Toyota Mr2 Supercharged and never had a problem with this ECU. NEVER>

I've just put $800 into my wife's 05 for a new "Powertrain" PCM. This car has 60,000 miles!!!!! Don't even pretend to disclaimer these junk Chysler parts, this car is a NA and gently driven by a mature driver and not a Turbo w loads of heat. Put away all the excuses, junk engineering is junk period.

This is exactly why 26 years ago went to Toyota.

 

[Jtweedie]

Agreed. The car is wonderfully functional and a delight to drive, but unfortunately it always seems to have something going wrong with it. It's my wife's car and it's her favorite ever, but even she is now ready to buy a new car and be done with it. After my last post I bit the bullet and took it to the local dealer for a diagnostic check (I figured that $120 wasn't too bad for a complete check that would no doubt check things I couldn't do without their specialized equipment). They decided the problem was that both oxygen sensors weren't functioning, but they could fix that for $400. I told them it was highly unlikely that both sensors would fail simultaneously but they were sure new sensors would cure the problem. Um, no. I replaced the sensors myself with OEM units for $90, but, surprise! the check engine light still shines brightly and error codes P0031 and 37 still come up like old friends. Did your new PCM solve your 05's problem?

 

[ImperialCrown]

Mopar has moved away from 'remanufactured' PCMs and now offers only new blank (generic) PCMs that have the correct program installed at the dealer for the particular car. The aftermarket is still offering the PCMs that may get caught in a 'revolving door' of sale/return/rebox/restock/sale. It is a crapshoot.
'New' is a much more reliable way, even if it is 3x the cost. Otherwise it might take 2 or 3 reman PCMs to get a good one.
Rebuilt or reman PCMs have a fairly poor record. There is no actual circuit board level of repair and no way to test the PCM for every possible contingency or failure mode. 'Rebuilt' or 'reman' is a misnomer.
Of course, 'hard failures' are obvious and the PCM is likely discarded. The vendors don't have a test stand in the shop where the PCM can be run under 'real-world' conditions.
See the 'Discussion' section on TSB # 18-006-04:
http://www.ertyu.org/steven_nikkel/neontsbs/2004/18-006-04.pdf

 

[pt006]

IC; interesting TSB above. After reading most of it I realized the complexity and level of knowledge required to install an engine computer properly. Certainly not plug and play. Special connecting cord required? Who knew!

Tim and JT; I have had several mopars with computers going back to the 80's. None, I repeat none have had a bad computer. Most problems are caused by bad/weak connectors, wiring, or sensor problems. The big issue is that nobody [including the rebuilders] can tell you if your computer is or is not bad. Nor can most dealers. There is a specific procedure to test PCM's and TCM's that may include running the car on a lift and disconnecting certain sensors and then rereading the results. Then repeating several other steps in order to get sufficient info to give a correct diagnosis. Simply plugging in the factory readers may give answers to simple problems. For more complex issues, more complicated testing may have to be done.

 

[pt006]

JT; somewhere on the exhaust system there is a ground strap which may rust and lose conductivity. NEVER use silicone on the o2 sensor plug connectors. Also, clean the grounds on the inner left front fender.

 

[valiant67]

Personally I'm seriously believing all these PT Cruiser's PCM's are a ton of crap. I'm listening to all these serious money losing "guess" swaps, severe money being sadly wasted and the bottom line seems to be this Chrysler part(s) is just junk waiting to fail. This thread being 2 years old is proof.
Don't get me started on a user UNFRIEDLY manual.

I have 425,000 miles on my Toyota Mr2 Supercharged and never had a problem with this ECU. NEVER>

I've just put $800 into my wife's 05 for a new "Powertrain" PCM. This car has 60,000 miles!!!!! Don't even pretend to disclaimer these junk Chysler parts, this car is a NA and gently driven by a mature driver and not a Turbo w loads of heat. Put away all the excuses, junk engineering is junk period.

This is exactly why 26 years ago went to Toyota.

And my 1981 Mirada was still running on the original air cleaner mounted computer computer when I sold it last month. That's 34 years of service from "junk" parts. Same for my 99 Dakota, only 16 years of service from that "junk" computer.

 

[ImperialCrown]

In the Powertrain Diagnostic Procedures book, the PCM is generally the 'last house on the block' when it comes to blame for a fault code. All troubleshooting steps must be followed in order before condemning the PCM. Except for fault codes P0601 and P0602 which indicate internal PCM chip failures, the PCM must be the last suspect.
The PCM comes with an 8 year/80K mile federal extended emissions warranty. It covers the unit as well as authorized software updates. You really can't do much better than that.
The factory does not recommend swapping PCMs for testing purposes. The VTSS-equipped option can be passed between modules to a non-VTSS vehicle, poison the BCM after the module 'handshake' and render the vehicle as a 'start/stall' that now needs 2 modules replaced.

 

[Looperx]

Argh, add me to the list of sufferers:

2005 PT Cruiser GT (2.4 Turbo) about 50k miles

Current symptoms:
1. P0031 & P0037 codes, come on intermittently, mostly on, but sometimes CEL goes away and they clear (noticed this usually happens after I drive a lot, on higher RPM) no other codes currently or previously
2. Very rare power loss (maybe once a month and only when CEL with 31/37 codes is on), pushing the accelerator pedal does nothing (as if there is no fuel flowing), RPM fall and fluctuate a bit, then after a couple of seconds the power comes back as normal. On couple of occasions the dashboard lights/functionalities went off, there was a chime and then all of dashboard lights flashed and came on back as normal.
3. Voltage fluctuation / flickering lights on lower RPM. Checking voltage at battery shows normal voltage flow @ approx 13.6/13.75 volts (don't remember exactly)

Tried looking at O2 sensor heater voltages through live data, but since they are PWM they fluctuate between 0 an 0.9 volts (as they should) so how the hell am I supposed to know that the voltage is lower than it should be. this is frustrating

 

[Jtweedie]

Welcome to the club, Looperx, sorry. Your symptoms are exactly the same as mine (which began at about 112,000 mi.; I now have 113,000 mi. on my 2004 2.4 Turbo) - except that I don't have the lights flickering issue so I suspect that may be a separate problem. The manual says to check for a poor ground connection at the instrument cluster for that problem. My P0031 and 37 issues began randomly just like yours but eventually settled into a constant condition. However, after resetting the ECM a couple of times recently (disconnect and reconnect the battery) the power loss/stalling problem hasn't resurfaced for several days.

 

[Looperx]

Welcome to the club, Looperx, sorry. Your symptoms are exactly the same as mine (which began at about 112,000 mi.; I now have 113,000 mi. on my 2004 2.4 Turbo) - except that I don't have the lights flickering issue so I suspect that may be a separate problem. The manual says to check for a poor ground connection at the instrument cluster for that problem. My P0031 and 37 issues began randomly just like yours but eventually settled into a constant condition. However, after resetting the ECM a couple of times recently (disconnect and reconnect the battery) the power loss/stalling problem hasn't resurfaced for several days.

Thanks for chiming in Jtweedie,
So looking at the "club" of PT owners that have 0031/0037 code problem, I guess its officially a quirk of GT models... I wonder if I should just clear them every time through Bluetooth OBD adapter and just carry on.. And yeah, I suspected the flickering light/voltage problem to be a separate thing all the way (although I secretly was hoping that was causing low voltage in sensor heaters).

Regarding the power loss, how often does that happen?

 

[Jtweedie]

The CEL is always on now (it was only sporadic for a while), but the power loss only occurs after the car has been driven - even for just a quick shopping trip - then re-started for the return trip or next leg. --And it's getting worse as time goes on. This makes me suspect it is related to an electronic component changing value due to heat-soak, probably in the ECM. Having replaced the OEM ECM with a "rebuilt" unit and having it perform perfectly when it was cold, then crashing entirely on the return trip (the car wouldn't even re-start after it quit) further supports this hypothesis. Another odd quirk involving the "rebuilt" ECM is that it's error codes were P0032 and 38 - Oxygen Sensor Heater Voltage Too High instead of too low, which indicates that the same inputs from the Oxygen Sensor circuits were being interpreted differently by the ECM - suggesting that the faulty component is in the ECM instead of the external sensor circuits. As I mentioned in an earlier post replacing the "rebuilt" unit with the OEM unit at least made the car driveable again, and oddly, I haven't experienced the power loss problem since I reinstalled it. After clearing the codes manually through the OBD port they usually re-set immediately, although early in the game they would sometimes stay off for a while.

Have you checked your ECM connectors for presence of oil? On mine the second one in from the passenger side (looking from the front of the car) appears to be weeping a brownish oil residue. I clean it every time I troubleshoot the thing, but it always recurs. At first I thought it might be oil wicking up from the cam position sensor or the power steering pressure sensor - both of which were leaking - but replacing them and thoroughly cleaning the wiring loom didn't help.

Another possible link in the failure chain is that shortly before the CEL problems started I had an overheating incident caused by a failed radiator cap and radiator. The overheating was severe enough to trigger the idiot light, but was brought under control fairly rapidly, and the engine itself shows no sign of mechanical damage (no oil consumption or head gasket leakage). ...Speaking of which, I recommend that all PT owners check their radiator caps regularly and replace them immediately if any signs of wear appear. What I eventually discovered was that my radiator had a small weep at the header tank - which I was keeping an eye on but didn't replace right away - but the loss of coolant wasn't apparent because upon cooling the faulty radiator cap allowed air to replace the lost coolant instead of sucking it out of the expansion tank. Therefore, the expansion tank level always stayed the same. Live and learn.

 

[Jtweedie]

Quick update: when I replaced both oxygen sensors I cut the pigtail off one of them to use as a convenient way of accessing the Oxygen sensor circuit for testing for shorts or high resistance. When putting this to use today I discovered that the inside of the old upstream oxygen sensor connector was saturated with oil. This could cause a high-resistance short across the terminals so it could be part of the problem. I haven't yet verified whether or not the resistances are off (I'm still wrestling with the fool connector, trying to get it off) but I thought I'd post this now in case anyone else is actively pursuing this line of investigation. I'll post my results as soon as I can get some readings.

 

[Jtweedie]

No joy. After cleaning the oily O2 sensor connector (computer side; the new O2 sensor side was clean and I didn't want to risk contaminating it with solvent) I was able to check for shorts and resistance (I had previously checked all other ground wires, and found them clean and tight). With the ECM disconnected one white wire was a solid ground (.3 ohm), and all others (the other white lead, black, and grey) were completely open circuits, as they should be, and I got the same results for both O2 sensor circuits. Disappointing, yes, but that's one more possibility eliminated. I guess it's back to the dealer now to see if he'll sell me a new $850 ECM - the final frontier. I'll let you know what happens. Thanks to everyone for your input.

 

[ImperialCrown]

'Voltage low' codes are generally a short-to-ground, that pulls voltage down. 'Voltage high' codes are generally an open or high-resistance circuit that leaves the voltage high because it can't complete the circuit, has no circuit load and has nowhere to go.
Motor oil and ATF won't really conduct voltage. They are an insulator.

 

[Looperx]

Another possible link in the failure chain is that shortly before the CEL problems started I had an overheating incident caused by a failed radiator cap and radiator. The overheating was severe enough to trigger the idiot light, but was brought under control fairly rapidly, and the engine itself shows no sign of mechanical damage (no oil consumption or head gasket leakage)..

I just realized something: I redacted your quote to the relevant part above... Looks like the previous owner of my vehicle did not take much care of it, because I am seeing both oil consumption between oil changes and a bit of oil leak from head gasket into the shaft where the first spark plug sits. My trouble with codes may as well be related to previous owner overheating the vehicle (he admitted to be a fast and aggressive driver when I gave him a call today) and the ECM being sensitive to said overheating (+ maybe due to a crappy voltage reading algorithm by whoever wrote the ECM firmware). BTW, since the cold weather started the CEL has been off for the record time now since summer, should I invest some time into thermally insulating it from engine and seeing if it makes the difference?

 

[george w]

You may as well bite the bullet and replace the PCM with new. These recurring codes are erroneous and are indicative of a bad PCM. It get's really hot under the hood. I'm sure you've had to replace the washer nozzles because they get baked to a crisp from the heat. This heat is most likely the cause of the PCM deterioration as well. The PCM should have been positioned either in the passenger compartment or in the front of the car where it could receive cooling air flow. In the case of my PT the occurance of the two codes became more frequent as time went on but never affected the way the car ran. it has always run perfectly. Maybe if the PCM were left in the car longer maybe those other symptoms would have developed.