SIA electronics for ECM / PCM / ECU repair?

RV-TJ

RV-TJ

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Peoria, IL
I've been reading here and there about availability of the ECU (computer) for the TJ being obsolete from Mopar. SIA Electronics in Tilden, IL (east of St Louis) seems to specialize in repair / refurbish of these.

*This is not an ad —- I am not advocating their use! I simply didn't know if anyone had used them or knew of them....maybe check them out?

*Also — I pick up my 3rd Jeep (2nd TJ) in a week and I am not in the need of a PCM....just throwing this out there !!!!

http://siaelec.com/
 
I live a few miles up the road from SIA and I have heard several good things about these guys from local mechanics.

I am dropping off a PCM from my 05 TJ 4.0 auto with the dreaded p0031, p0037, p0051, p0057 o2 heater circuit codes after determining the wiring and sensors are fine. Hopefully my 3 hours of back probing and tracing sensors and wires will be worth it! We will see if they can fix it!!
 
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bmpcamry09 said:
I live a few miles up the road from SIA and I have heard several good things about these guys from local mechanics.

I am dropping off a PCM from my 05 TJ 4.0 auto with the dreaded p0031, p0037, p0051, p0057 o2 heater circuit codes after determining the wiring and sensors are fine. Hopefully my 3 hours of back probing and tracing sensors and wires will be worth it! We will see if they can fix it!!
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Please follow up with your results. Every summer when it heats up to like 90 degrees I get similar codes, 0032, 0038, 0052 and 0058.

I also read that the precats go bad and cause these error codes, so could be the PCM, could be the precats.
 
skrelnik said:
Please follow up with your results. Every summer when it heats up to like 90 degrees I get similar codes, 0032, 0038, 0052 and 0058.

I also read that the precats go bad and cause these error codes, so could be the PCM, could be the precats.
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Yeah I’m not sure about those codes but I know with the o2 heater circuit codes, if the sensors themselves test good and the wiring and grounds are good, it’s likely a pcm especially in 05 and 06 models. Precats would indicate codes such as inefficiency codes and other o2 codes. Dropping off the pcm as we speak and I will let you know!
 
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SIA electronics replaced the o2 sensor driver inside the PCM for $120. After a few minutes of driving the CEL came back on with the same 4 codes. Engine does seem to be running better though after the PCM repair

I give up! Wiring all checked out. It runs great. We don’t have emissions testing where I live either. May just have to unplug the CEL build behind the dash to keep the light off 😂
 
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FINAL UPDATE! After driving the Jeep for a day, the light went off by itself. Checked it for codes again and it’s all clear! Guess the rebuilt pcm just had to do a relearn process. I checked all the Readings and the sensors are finally communicating with the PCM. So in other words, if you are having similar issues and Itraced everything back to a PCM issue, check out SIA electronics!
 
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bmpcamry09,

I'm going through the same headache myself. One repair shop found nothing wrong, re-flash the PCM, and the errors popped back. I've ruled out all the wiring, connectors, PCM plugs etc. Quick question. When you said SIA replaced the O2 driver, do you know if it was a software/firmware driver, or a physical component on the board? I'd like to give the repair shop one more crack at the fix if i can point them in the right direction. If they can't fix it, I'll give SIA a shot.
 
They replaced the actual hardware driver for the o2 heater circuit on the board. Unfortunately, it was short lived and shorted out again and I had all the codes again. All 4 codes returned plus the computer wouldn’t go into the “ready” state.

This time, I bought a remanufactured pcm from Flagship 1 for around $500 and I never had any more issues and the CEL remained off. Well worth the money. I have since sold the Jeep but it had no issue at all

For poop and laughter I peeled apart the original pcm that SIA had apart, and it was FULL of corrosion. Guessing that was the main issue.
 
Nightrider7731 said:
Damn. Not the end result I was looking for. However, thanks for the quick response and update.
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Talk to Mark, @Wranglerfix He might be able to help you out. Several people on this site, including myself, have purchased PCM‘s from him with success.

I didn’t have any O2 sensor issues though in my ‘06. Mine was all transmission hard shift related.
 
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Thanks. I'll keep him in mind. I have a generic P0700 plus P0562 to go along with the O2 errors. Shifting issues as well. Others around the boards have report similar issues as a bundle. This is actually my son's jeep (he has mine), so I can't leave him hung out to dry. The part that really sucks is that these costs don't count towards the emissions waiver in Virginia if they fail. I may have to use the old PCM for target practice while Virginia still lets us have our guns!
 
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I had P0700 too, and another related to the transmission (don't remember the code of the top of my head) saying it was overheated, I have a trans temp gauge and it wasn't showing anywhere close to overheated. I had the hard shift from 1-2.

I got a Wranglerfix PCM last summer and have had no more codes or hard shifts since.
 
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Nightrider7731 said:
Thanks. I'll keep him in mind. I have a generic P0700 plus P0562 to go along with the O2 errors. Shifting issues as well. Others around the boards have report similar issues as a bundle. This is actually my son's jeep (he has mine), so I can't leave him hung out to dry. The part that really sucks is that these costs don't count towards the emissions waiver in Virginia if they fail. I may have to use the old PCM for target practice while Virginia still lets us have our guns!
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It’s definitely Pcm failure… Speaking of guns, the 0700 code is like a .357 magnum to the tcm processor!! 🤯

Hard shift from 1st to 2nd when cold is pcm failure as well.


How old is the battery? The 0562 is low voltage. If it is over a year old, I would change it out.

Thanks,

Mark
 
The battery tested a hair low and failed at the parts store at load. It was several years old, so I swapped it out a few back just before I parked the jeep for a bunch of other work. Alternator's pushing 14.3V, diodes tested good, and less than 0.02 AC interference. I figure it's the PCM, but G7 found no issues. I'd love to have a schematic of the PCU. I figure all four are being feed from a single cap somewhere. I figure I'll send it out to someone else and maybe pull the trigger on a refurb. It figures I just got a small bonus that will barely cover a new PCM. Easy come, easy go.
 
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Nightrider7731 said:
The battery tested a hair low and failed at the parts store at load. It was several years old, so I swapped it out a few back just before I parked the jeep for a bunch of other work. Alternator's pushing 14.3V, diodes tested good, and less than 0.02 AC interference. I figure it's the PCM, but G7 found no issues. I'd love to have a schematic of the PCU. I figure all four are being feed from a single cap somewhere. I figure I'll send it out to someone else and maybe pull the trigger on a refurb. It figures I just got a small bonus that will barely cover a new PCM. Easy come, easy go.
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I understand and empathize with you. Do you have an 05-06 TJ? If so, PLEASE do not waste your money trying to repair the oem part. Other years are repairable, just not those two.

I have a few pcms that have a small crack In a plug that I can knock a $100 bucks off of for you if it is an 05-06. I have attached a photo...Same warranty, same performance.

Thanks,

Mark

9E4C49F0-C908-4A0F-ABC9-A41A2970BB54.jpeg
 
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