Crazy Intermittent Starting Problem, No PCM Comm....Help please!

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Oct 1, 2015 | 12:55 AM

jrayheyhey

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Cruising

Joined: Mar 2012

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Crazy Intermittent Starting Problem, No PCM Comm....Help please!

Hi Guys, I have a 2000 Vette with a crazy intermittent starting problem. Hoping for a lead, on this issue. What happens is this. I turn the key and the car fires up for one second then dies. Cluster shows reduce power message even though not running. I then look at all the DTC codes in ICP and it shows no communication to all modules. So what I do at this point is get out of the car and press down on the fuse box a few times and this seems to make communication the PCM and all other modules possible, I then go back and then it will start up. This usually seems to do the trick..

I have been reading up, and understand the boot in the door wiring could be the culprit, especially since this car has lambo doors. When there is no communication I notice neither windows go up or down, but seat works, AC and other electrical components work. Common sense tells me check all fuses which I did and they were good. I am thinking now to get a new fuse box. Also read a serial bus cable is connected to the fuse box which is exactly where I am pushing to make pcm communication again. Any thoughts or ideas would greatly be appreciated. J

Oct 1, 2015 | 06:11 AM

dadaroo

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Joined: Mar 2011

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From: Columbia SC

The Serial Bus does NOT run through any fuse box. I need to think a little on where to start diagnostics.

Oct 1, 2015 | 07:25 AM

garline14

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Joined: Mar 2014

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From: Houma Louisiana

I had a similar issue a week ago with my 98 Coupe. The problem with mine was that the contacts on my ignition switch were burnt, I did the ignition switch repair and all is good now. When I would turn the key to start my car, the gauges didnt sweep, I did have several messages pop up like reduced engine power, service traction control, low voltage, check engine light came on as well. The car would start then die immediately. Sometimes I would turn the key and everything went black, no dash lights but all windows, lights, radio worked. Not sure if the switch could be your issue, double check the grounds, fuses, relays, and be sure they are all good.

Oct 6, 2015 | 11:35 PM

jrayheyhey

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Cruising

Joined: Mar 2012

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I might end up trying the ignition switch eventually, thank you. when this problem occurs (which is almost every time I go to start the car), my remedy is to press down on the engine fuse box. This seems to make everything make contact and work until next morning. Now I am considering purchasing a new fuse box and swapping mine out. It's not super expensive and something I believe I could handle. Seems to me like one of the little connectors on the bottom of the fuse box may have lost contact and when I press on the the whole fuse box the car wakes up and starts. And if that doesn't work, I plan on unplugging all the computer modules one by one to see if a short is causing this problem. Any ideas or feedback appreciated. Thanks.

Oct 7, 2015 | 06:16 AM

dadaroo

Le Mans Master

Joined: Mar 2011

Posts: 6,835

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From: Columbia SC

Make sure the two Red wires to the fuse box are tight. If that does not do it I would lift the box up and unplug the connectors, inspect and reconnect. I have seen a couple of internal fuse box issues so it is possible that's it.