How often does the PCM fail?

I have a 2000 with 180k miles that is throwing the P0203 code for injector circuit malfunction. I'm been up and down the line checking for worn insulation and testing circuits but can't find anything. I saw somewhere that people have seen that code on similar age Chrysler vehicles. Has anyone else seen PCM failures on those or similar models?

I've replaced all of the injectors already.

PCM failure is very uncommon, but possible. If you have exhausted all of the common and usual reason for a P0203 code, you might suspect that the PCM is faulty. Have you checked the PCM wire plug and the individual wire pin contacts on the PCM side as well as the injector side ?

I have been experiencing a P0201 code and have determined that the contacts inside the injector wire plug are corroded. I will be grafting on a better condition injector wire plug and installing a good used injector this weekend.

P0203 Possible causes

•Faulty fuel injector 3
•Fuel Injector 3 harness is open or shorted
•Fuel injector 3 circuit poor electrical connection

Have you put a noid light on the injector to check for drive? The only time I have seen an ECU fail was when an injector shorted and burned out the driver in the ECM.

(1)Swap a couple of injectors and see if the fault moves to a different cylinder.
(2)Clean the injector contacts.
(3)Clean the ECM connector/contacts
(4)Get a long set of ohmmeter leads and check resistance from end to end on the injector wiring to the ECM.

old_man said:

Have you put a noid light on the injector to check for drive? The only time I have seen an ECU fail was when an injector shorted and burned out the driver in the ECM.

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Out of curiosity, do you know the Jeep ECU's have current limiters on the injector drivers and didn't work in that case?