2005 and 2006 Jeep TJs/LJs have a Powertrain Control Module (PCM) that is notorious for failing. Unfortunately, you will not find any OEM replacements which will leave you with three options: repair your unit, find a used unit pulled from another vehicle, or replace your unit with a refurbished one.
A long trail of failures
Once I diagnosed my PCM as faulty I immediately searched online for a replacement on the Mopar website as well as my local auto parts stores websites without any luck.
Next, I called my local Jeep dealership who informed me OEM PCMs were no longer produced for my year and model vehicle. The Jeep dealership informed me that if I did find a PCM that was compatible with my vehicle they could reflash it to my VIN for just over $100.
That led to visiting local pick-n-pulls, but as it turns out it is not easy to find a compatible PCM with the matching last four of the serial number. I briefly looked for private sellers parting jeeps, but with prices around $400-500 and no guarantee of a functioning unit, I decided this option was not worth the gamble. There are multiple businesses online offering rebuilt/refurbished units but with an average price tag of $570-750 this was going to be a last resort. So, I opted for sending my unit out for repair.
Online reviews led me to believe that this is an industry riddled with fraud but after finding a company that appeared reputable, I sent my PCM off to get fixed for approximately $100 at S.I.A. Electronics. A few weeks later the company called to inform me that the processor in the transmission control unit was damaged beyond repair.
Unfortunately, the 05/06 PCM is a single unit that houses both the Engine Control Unit and the Transmission Control Unit so an irreparable TCU rendered the entire PCM useless. It was then through chance and desperate hunting for an affordable unit on eBay that I stumbled upon Ares Technologies which is a company that produces various types of remanufactured vehicle electronic control modules.
My PCM was listed for a price of $250 including the VIN programming which initially made me skeptical due to its price in comparison to other refurbished units I had previously looked at. After verifying they were a legitimate company and that their product came with a 30-day return policy and a lifetime warranty I decided it was worth a try.
I was a little surprised when I opened the package. I received a PCM that was smaller and significantly lighter than I anticipated. In fact, the remanufactured PCM was more than a pound and a half lighter than the stock unit. It was programmed to my VIN as advertised so my chipped key worked and the PCM was updated with the most recent software from the original manufacturer. I was thrilled that this PCM was fully functional and the lifetime-warranty brings me confidence that I will not have any future issues with this product. If you happen to find yourself having problems with any of your vehicles electronic control modules, I suggest taking a look at Ares Technologies for an affordable solution.