I have a 1997 Caravan 3.0. Here lately it seems the ECM is "wistling" after I turn the van off. It does it for a minute or so, then a couple clicks and it stops. I traced the noise to (as far as I can tell) the ECM. Anyone heard of this? ECM about to go bad?

 

Been cruising forums for many years and this is a first.

 

The van finaly craped out on us. I checked the codes, and got a code 11, so I changed out the crank sensor. Still didn't run. So a friend brought over a small hand held scanner, and it told me the cam sensor. So after finding out it was under the dist. cap, I changed it out and still no go. The scanner still says cam sensor circuit malfunction. (blinks a 54 code on the engine light too)

Anyone got any ideas? computer bad?

 

Verify each sensor is getting a reference voltage from the PCM (8vdc?) on the orange wire at both connectors. Verify each sensor ground is good at the black wire. Check continuity of the signal wire at both sensors is good from the sensor to the PCM. If all is well consider changing both with OEM sensors if you didn't. After that start looking for a PCM.

On 3rd generation vans either sensor can generate a cam sensor code or a crank sensor code.

 

Thanks cougar41, I will check tonight.
If it ends up being the PCM, can I replace it? I heard I can't,that the dealership had to do it, cause they can't be switched from one vehicle to another.

 

If that were the case there's dozens of online sources and parts stores who must spend millions in lawyer fees fending of thousands of lawsuits for fraud.

If you heard that specific to your 1997 van, it's garbage. Autozone for one sells them. There are several popular on line sources. Some cost as little as $100 and come with a lifetime warranty. You give them your vans VIN number and they program it based on that. All you have to do is install it.

 

Thats good news! The guy that told me that, said it had something to do with the "fat plastic top" key...

Anyway, I checked the grounds, both good. The cam sensor had 8.9v, was I think 8.3v at the crank sensor. I can't figure out where to check conectivity of the signal wire at the PCM. BUT while I had the key switch on, checking everything, I leaned over above the PCM to see where to test it at, and the stupid thing was "whistling" again.
I gues I'll try to unbolt a few things to see if I can't get to the PCM a little easier

 

Thank you very much for your help, btw!!!

 

Cam sensor sig comes into the PCM on connector C1 pin 33 (tan/yellow wire). Crank sig at C1 pin 32 (grey/black wire). Disconnect the battery before disconnecting the PCM to avoid potential damage. I think you have to anyway to get at the PCM.