My friend is having trouble with his PCM. Wants to test his jeep with my unit...95 XJ.

What is the difference between the older PCM with the heatsink compared with the one with the 3 capacitors?

Can these PCM units be swapped from one Cherokee to another?

 

I think Renix ECUs can be swapped with other Renix ECUs. OBD-I's are swappable with other OB-I's, IIs with IIs.

But I could be wrong.

 

Could someone confirm the differences between the two ECU OBD I models and whether they can be interchanged between the two jeeps...

 

91 to 95 OBDI should work as long as both vehicles are the same. OBDII PCMs will not work in a 95 or older vehicle.

 

Got it. Thanks. What's the difference between the OBDI models - older ones with heatsinks vs newer with capacitors

 

A few more sensors, more data streeam, and more diagnostic trouble codes are just a couple of things OBDII brings to the table. OBDII trouble codes and the data link connector are standardized and all the same for every vehicle sold in the States since 1996. Before that every car maker had their own data link connector and different trouble codes, sometimes you could not even link up to their PCM without their scan tool.