seems like we have a major problem here. on the 308's. mine is not turning over with the key. new battrey(1000 cca) changed out the key and transponder, ecm from a running car. still nothing. no clicks ,buzzings ,bells.just dead. but when i pull out key ,all dash lights flash for about 10 sec and a here a timed clicking from behind the speedo.. i heard that you could only try and start it 6 times then it goes into super lock down. used to crank at times then not. been going on for about a year now. put old stuff back in and does same thing. long as key is in no flashes .only for 10 sec after removing key.

 

It is sounds like that there are very low voltage in the system. Maybe it is a grounding, or B+ cabel connection problem somewhere in the system.

 

removed speedo from my spare to see whats behind it . 2 boxes. 1 is the transponder and the other is key buzzer, i guess.. then i undid all nuts , screws on wiring that i could find had it on lift so i could get to all. changed key ring sensor. still nothing. only thing not changed is bmc. that next

 

What exactly?

Have you a wiring diagram (downloaded from links in this forum)

The battery is new? what's it's voltage right now?

Have you checked the major ground straps and power leads? One next to the bell housing - obvious on a ramp. Two large diameter power cables that run out the inner front wings, one connected to a brass bolt/nut, the other to the fuse boxes on the other side. There's also an interconnect between the two fuse boxes, these ring terminals need checked for oxidization.

Earths in the car, one on a post drivers side footwell under the carpet.

Being frank - it's a lot easier to fault find without introducing major electronic parts from other cars. They have to be from the exact same model, year and month to be of 100%. You can't sling a 99 in a 00, or an 01 in a 00.....

Put it back together and go back to basics.

Sounds like a fault in the wiring/power to the IPK, all security/starting go thru this module, or module fault itself - if it's supply is dodgy the car will not start, highly unlikely a security issue.

I found bare wires earthing behind the roof lining for the sun visor causing all sorts of issues. For example.

If it's a cable harness fault it's difficult to diagnose and a fair bit of work. Any break in the canbus will give many weird issues.

Need detailed info to help further

 

don't see why not. all the part numbers are the same except the computer, that changed in 2000. i mostly work on american iron. that's why i keep a lot of used jag parts on the shelf to check things i think may be it. jag parts are not always to be found and not cheap. but like this one sometimes that doesn't work. been lucky up to this one. going to try something diff and put stuff from 2000 to 1999 and see what happens.. as the old song one piece at time

 

Problems like this are 99% of the time related to the weak ground. That's where I would start. Once ALL ground points are cleaned of corrosion, and tight, I'd go at it with a voltmeter,....step by step, while looking at the wiring diagram. It takes patience, several breaks, some "refreshments", and a positive attitude. Cussing only helps when you strip your knuckles, or when you scratch your Rolex that you forgot to remove.

 

The starting point for fault-finding is the starter relay, as this is the interface between the low power security modules & the high power supply to the starter solenoid.

The problem will lie in 1 of the following 2 areas:

1) The low power security circuits & starter relay coil drive-they decide if the starter relay coil is energised.

2) The high power circuits that take the high current drive from the starter relay to the actual starter motor solenoid.

The starter relay is energised by the Body Processor Module (BPM), so you need to monitor the output of the BPM to see if it's actually energising the starter relay when the faults appear. There is a single output from the BPM which energises the starter relay-it does this by earthing 1 side of the starter relay coil-the other side is connected to the +12v supply from the ignition switch.

If the starter relay is being correctly energised, but the fault is still there & the engine won't crank over-then the fault will lie in the high power supply lines to the starter motor, or the ground straps-or it could be the starter relay itself.

If the BPM doesn't energise the starter relay when the fault appears, then the fault will lie with the BPM-or the modules that drive it-such as the Key Transponder Module.

The fault could also be due to poor ground connections on the car-there are several grounding studs around the bodyshell which have terminals connected to them. Some are under the bonnet, in the passenger compartment, or in the boot.

You really need to download the circuit diagrams from the JTIS, which is available on this site. Go to Fig 3.2, which is the Battery, Starter & Charging circuit diagram for the Supercharged cars. Locate the starter relay (EM50) & then you can find the connectors & modules that drive the relay-along with the component locations.

You really can't do much more until you get the circuit diagrams & understand how the system works for starting the car. The wiring diagrams also show all the ground stud locations on the vehicle, so go around all of these & make sure they are all tight with no corrosion.

It's a slow, steady & logical process-so it will take time...

 

For computerized modules, most of the time the part number AND the VCATs code, which is basically a software version, need to match or be known compatible.

 

Wow this is a scary scenario...

 

a ah ha ... the other nigt i was playing with it again and in the dark i could see a little red light by the gear shift blinking. as i don't have owners manual , this the alarm mode light?

 

Yes, this flashes once the alarm system is armed.