99 Cherokee XJ PCM replacement question

Blaze

Blaze

The Jeeper Reaper
Joined
Aug 9, 2005
Location
Wake Forest, NC
So question that I forget the answer to. My son's 99 XJ is acting weird, stalling and such, but throwing no codes to allow us to chase issue. Been parts shotgunning it with spare parts but I think the PCM might be the culprit. I bought one off of eBay for a 99 and just tried to install it. Now, I know back when I had the shop I swapped PCMs without ever having to flash them. Just bolted them in and rolled on. This one I installed and the thing was like "no sir, I don't like it" and was misfiring and none of the gauges worked or anything. Put old PCM back in and it fired right back up.

Do I need to get this thing flashed or is the PCM junk? It was used and the dumbass shipped it in a small flat rate box with no packing material, just the thing jammed in there. I wouldn't be surprised if it got fuxored in transit.
 
it's junk. reflashing is an option but it may not work. I would try to get my money back.


If you were closer I would let you use my spare ECU for testing purposes. FYI upstream 02 will cause stalling and low power, these jeeps like NTK o2 sensors.
 
Jeff B said:
it's junk. reflashing is an option but it may not work. I would try to get my money back.


If you were closer I would let you use my spare ECU for testing purposes. FYI upstream 02 will cause stalling and low power, these jeeps like NTK o2 sensors.
Click to expand...
@Jeff B nailed it
The only "flashing" you can do to those PCMs is entering VIN, mileage and theft info (if SKIM equipped)
Aside from that, outside of a tuner, nothing else.
You have a junk PCM
 
Jody Treadway said:
@Jeff B nailed it
The only "flashing" you can do to those PCMs is entering VIN, mileage and theft info (if SKIM equipped)
Aside from that, outside of a tuner, nothing else.
You have a junk PCM
Click to expand...
Just an add on. In SBEC3 I can re-flash, change VIN, SKIM partnumber mileage etc. Also change some of configuration values such as EGR . Not sure which PCM type is in 99 XJ . Most of work has been focused on 98-2002 300m. I can disable SKIM in NGC3 & NGC4 PCMs. ( also SEBC3) The skim value has many setting. ie OFF, learned, waiting to be learned,failed,locked etc. No sure what each value is but if someone needs help -- reach out.
Also you can disable SKIM on FCA 2004-2010 with DIY software and ELM 327 BT.
 
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