Security System (I think)
Good morning to all - HELP PLEASE. I am John W and currently working in Izmir, Turkey. A few months ago I had bought a high mileage 90 rag top from California and had it shipped here. This is really starting to be embarrasing. This is the 3rd vette that I have owned in my life and unfortunately I have no mechanical or electrical sense - I am a driver not a fixer. Anyway, the problem is that ever since I have had the car here there is SOMETHING that runs the battery down while it is parked, so to fix that I had a batter cut off switch installed. I rarely use the car during the week and mostly use it to play with on the weekends. APPARENTLY there is another problem (electrical) with the car and that is for some reason, even though there is more than sufficient battery power, when you turn the key NOTHING HAPPENS. There is a very modern Ford dealership here and they have been helpful for a number of things and they seem to feel that there is something in the security system that says NO, DONT GIVE ANY ELECTRICITY ANYWHERE TO THIS CAR. If you jack the car up a little off the ground and lower it quickly so that the car takes a small jolt it is fine (that is to say it starts again), but that is not a fix. Does anybody have any ideas out there? I would appreciate it because the car is now in the dealership (Ford) again as we write. Thanks again, John W
Starting after a jolt is a classic sign of a bad stator on fuel pump. See my post of a few days ago in reference to fuel pump lifetime. The dealer should be able to capture a current waveform and tell you about the pump internals.
Anyone out there know the new RPM of a vette's fuel pump?
Also could be a bad starter or solenoid, but I don't know that problem as well. Apparently you give the starter a tap to free the solenoid.
Thanks - I will pass this on to the mechanics here. I really appreciate the help. John W
This is jwinizmir again - These are the words from the dealership here: "when the car doesn't start there is a flashing security warning light on the instrument panel. When everything is normal you put the ignition key on and the security light goes off, but when this problem occurs the security light always flashes even you turn the ignition on and even starter doesn't work and engine does not crank. When we apply direct 12 volts current to the starter motor engine cranks and starts to run."
Does this tell me that "maybe" the problem is the starter?
If the problem is not the starter and actually is in the antitheft system is there a way to bypass the antitheft system?
Is this a VATS problem? Try waiting 5 minutes after a non-start effort and try again. Also search the C4 tech forum here and I'm sure you will find more info. Also go to C4vettes.com
I would agree with the suggestion that it might be VATS related (i.e. the little resistor in the key talking to the Pass Key system to allow starting).
I would think the security light continuing to blink implies that the 'key' is not being seen by the VATS system.
As I understand it, if the contacts inside the ignition key are worn-out, or the contacts on the key 'resistor' are worn-out or dirty, it could create the symptom you are describing.
Does moving the key around in the ignition switch make any difference?
Has someone lubricated the ignition switch with something which might have caused this problem? (though I am not sure what should be used!)
Have you tried having a new key made (with the proper 'resistor' code -- 1-15)?
One other thing it might be is bad/dirty ground wire somewhere which needs to be loosened/re-tightened (e.g. behind the rug and kick-panel on the out-side foot area on the driver and passenger sides).
Do you have the service manual? If so, try checking the trouble-shooting section or giving it to the dealer to have them check it.
By the way, on the battery drain problem, do the interior lights stay on after closing the door (say beyond 15 seconds or so) or does the alarm go off once and awhile for no apparent reason?
If so, maybe your door switches are going bad (like ours did on our 94).
good luck and hope this helps...
Security and intermittent starting
Try this article by clicking on Tech Center above then knowledge base then search 'VATS'
1986-1987: Service Bulletin: Intermittent No-Start Condition Caused by Vehicle Anti-Theft System [Electrical and Ignition]
Other bulletins may help too.
Thanks for the long answer.
We have looked at the key solution last time. I have the key that came with the car and the dealer that I bought it from had two others made for me and it does not appear to be a key problem.
As far as the battery drain thing goes - The interior lights do go off as they should and the alarm has only gone off once or twice when I inadvertently set it off. The car usually stays in the garage in my house and I would have heard it if it went off any other time. Anyway, I have solved the battery drain problem by putting a battery disconnect switch under the hood. I am sure that is not the optimal way to correct the problem, but it works.
Thanks for trying to help, if you or anybody else can think of anything else I would be very happy to hear. Thanks again - John W
Mine would drain fast too but a new battery helped a lot. Does it start better? Did you find the no-start shake-it-up then starts problem?
The dealer that I bought the car from had told me that I needed a GM Part 16068654 to bypass the antitheft system. I have finally located somebody (painless performance company) that also indicates that part number so I have written an email to them asking about it. It is supposedly a computer chip part that should bypass the antitheft system. I am also wondering that if I bypass the antitheft system will my keys with the chip in them still work??? I dont know, I am still waiting for their answer. John W in Izmir
There was a very good post on this a while back. I don't know the link but copied it and have pasted it here. Don't know if the photo will show up tho so have added an attachment.
There's also a service bulletin that mentions a faulty VATS system ground but I don't recall the year. You can find it in 'Tech Center' 'Knowledge Base' etc. on the tab at the top of this screen.
GM No-Crank in vehicles with
Vehicle Anti-Theft System (VATS)
A No-Crank condition in GM vehicles with Vehicle Anti-Theft Systems may be caused by either a bad igintion key or a
problem in the ignition switch/VATS wiring harness. (Switch/harness assembly problems seem to be more common than
Test 1) Check the ignition key. Each key contains a resistance pellet. Remove the key and check the pellet’s resistance.
The chart below shows possible resistance values for ignition keys. If the key resistance matches one of the chart values,
go to Test 2. If the key’s resistance value doesn’t match one of the values in the chart, replace it with a new one. Your
GM dealer can provide part number information if you give him the VAT module identification number.
Test 2) Insert the ignition key in the ignition switch. Remove the lower dash bezel. Locate the two-terminal white connector
near the base of the steering column, and disconnect it. (See the next tip for a schematic.) Insert your ohmmeter
leads across the terminals of the connector half containing the white wires and measure the resistance. The resistance
value measured across the connector should match the key resistance. If it doesn’t, then the problem is in the switch/
harness assembly. Replace the assembly.
Resistance Value Chart for GM VATs (Lists possible resistance values, including acceptable ranges)
• 402 ohms (acceptable range 386-438)
• 523 ohms (acceptable range 502-564)
• 681 ohms (acceptable range 650-728)
• 887 ohms (acceptable range 850-942)
• 1130 ohms (acceptable range 1085-1195)
• 1470 ohms (acceptable range 1411-1549)
• 1870 ohms (acceptable range 1795-1965)
• 2370 ohms (acceptable range 2275-2485)
• 3010 ohms (acceptable range 2890-3150)
• 3740 ohms (acceptable range 3590-3910)
• 4750 ohms (acceptable range 4560-4960)
• 6040 ohms (acceptable range 5798-6302)
• 7500 ohms (acceptable range 7200-7820)
• 9530 ohms (acceptable range 9149-9931)
• 11800 ohms (acceptable range 11328-12292)
Temporary Fix for GM No-Crank in Vehicles
with Vehicle Anti-Theft System (VATS)
Experience suggests that VAT
ignition key failures are less
common than no-cranking conditions
caused by switch/harness
If you need to start a car to get it
into the shop, try this:
• Remove the ignition key and
measure the resistance of the pellet
in the key.
• Drop the steering column bezel
and disconnect the white wire
• Connect your sensor simulator across the terminals of the harness connected to the VATS module and “dial in” a
resistance equal to the key pellet resistance, or simply insert a fixed resistor of the correct value.
This bypasses the key/harness and, in many instances, it will allow you to start the vehicle and drive it into the shop.
This is wonderful. Thank you. I will forward this in the morning (it is now 9:30 PM here) to my mechanic at the FORD place.
Thanks again - John W
Got another idea for you:
The starter interrupt relay - Haynes manual says:"At the same time the alarm is triggered, the starter interrupt relay is energized, disabling the starter solenoid circuit. In order to conserve vehicle battery power, the alarm shuts off after three to seven minutes of operation and rearms. But once triggered, the starter interrupt relay will remain energized by the controller unit until the system has been properly disarmed"
The fact that the bump helps may mean the relay is stuck open when the controller wants it closed. Wire colors to this relay on my 94 are yellow, yellow, purple, and yellow/black per alldata. You can test this by unplugging the relay and putting a jumper wire on the two contacts that go to the starter solenoid and the neutral/clutch safety switch. I've attached a picture from alldata.
Let us know how it's going!
Owned and Operated by © 2000-2013 Corvette Action Center | |
© CORVETTE is a registered trademark of the General Motors Corporation & Chevrolet Motor Division. Neither Chevrolet Motor Division nor any subsidiaries of GM© shall bear any responsibility for CorvetteActionCenter.com content, comments, or advertising. CorvetteActionCenter.com is independent from GM© and is not affiliated with, sponsored or supported by GM©. Copyright/trademark/sales mark infringements are not intended, or implied. All Rights Reserved