Help! Have I fried my 2001 Caravan PCM?

I was attempting to bypass the low-pressure cycling switch to engage my air conditioning compressor using a jumper wire. I made a rookie mistake and touched the hot wire to the wrong end of the switch plug. The vehicle immediate shut off and now will only start by pressing the gas pedal. It runs rough and will not idle without gas. I received various fault codes (0122, 0117, 0107, 1478, 1599, 1496, and 1192) that all relate to low voltage sensed at various components. Is there no fuse or other in-line protection against such a power surge or perhaps some sort of reset on the PCM? Any assistance or diagnosis would be greatly appreciated. Thank you.

Pinky

Reply to
Pinky56
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It sounds as if you burnt up the 5 volt sensor supply that the PCM uses for the sensor circuit. You dont specify an engine size so I will assume its a

6 cyl. Check the Pink/yellow wire for 5 volts at the TPS sensor. If you have nothing Go to the PCM C2 connector and at pin 61 (it should be numbered on the connector) check for 5 volts with the key on. If not, see your local Dealer for a new PCM and it has to be programmed with the Scan tool. Let me know what you find.

Glenn Beasley Chrysler Tech

Reply to
damnnickname

Thank you very much for your reply Glenn. I checked that Pink/yellow wire at both the sensor (MAP) and at the PCM and have approx 5 volts with the key on. I also checked the sensor ground at both ends and they appear to be in tact. Any ideas? Is it possible there is a fusable link blown somewhere. Any ideas what this repair bill may run? By the way, your assumption about the engine size is correct (3.3L). Thanks again.

Pinky

Reply to
Pinky56

It was the PCM, I grounded out the sensor wire. $400 lesson.

Reply to
Pinky56

Why $400.00?

Glenn

Reply to
maxpower

Do a battery disconnect for about 2 min and restart the vehicle to see what fault codes have returned. You could have a sense wire shorted to ground. With the multiple codes you have, it may be another sensor that is affected and the test you just did on the TPS was good. see what codes came back. A scan tool would be very helpful to show what the sensor values are. Not a fusible link or fuse problem. A job like that may be from 2 to 4 hrs to diagnose and repair with the right books and scan tool may be cheaper.

Good luck

Glenn

Reply to
maxpower

The mechanic was able to find a used PCM at one of the local wreckers and then had it "flashed" (which I assume to mean reprogrammed) at Lordco. Total cost of repair job was a little over $400.

Reply to
Pinky56

Hmm ,you are a brave person to swap PCM's. you could have caused major problems by doing that, And $400 is to much money for a used PCM

Reply to
maxpower

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