Pontiac Grand Prix Starting Problem

malemannmalemann New Brunswick,CanadaMember Posts: 1
edited July 2015 in Pontiac
I have a problem with my Grand Prix....At time when I shut it off and attempt to restart....nothing happens. I tried replacing the alternator installed a new battery and the problem remains.
I discovered that if I simply un-hook the negative battery cable and replace back on the battery I will hear a clicking noise as if resetting get into the car turn the key and the car will start ..no boosting needed.
This problem has been going on for about 9 months now and each time the car refuses to start I follow the same procedure of removing and replacing the negative cable and car starts.
I have taken the car to a number of mechanics and they are puzzled...anyone with a possible solution of what could be the cause ?

Comments

  • imidazol97imidazol97 Crossroads of America I70 & I75 Member Posts: 25,907
    malemann said:


    I discovered that if I simply un-hook the negative battery cable and replace back on the battery I will hear a clicking noise as if resetting get into the car turn the key and the car will start ..no boosting needed.

    When you turn the key, is there a light saying security that flashes, indicating the VATS system which reads the resistor pellet on your key read the resistor and got a wrong resistance and locked the start enable for 3 minutes? When this happens, the gauges and lights and all work, but there's no cranking when you turn the key.

    From the Autozone charts, it looks like the PCM and BCM are both on the same fuse. Check your fuse listing in the owner manual in the glovebox and locate the various fuse boxes and which fuses are for Body Control Module and for Powertrain Control Module. What I was hoping is that there were separate fuses and you could remove one fuse when this is happening for a few minutes without disconnecting the battery and everything else losing power.

    If disconnecting the BCM fuse solved your problem when that computer booted then you could try replacing it--it may have to be done by someone able to reprogram it to the key resistance you have: I have no experience with your car and the key resistor.

    If disconnecting the PCM solved the problem when everything else stayed powered up and it rebooted after being off for several minutes, then you could consider how to handle that indication.

    It sounds like one of those is not letting the start process enable the start relay switch. When you disconnect the negative at the battery, those both reset and work again.

    2014 Malibu 2LT, 2015 Cruze 2LT,

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