Mechanics

IGNITION PROBLEMS

1990 Cadillac Deville

Electrical problem
1990 Cadillac Deville V8 Front Wheel Drive Automatic 150, 00 miles

This problem has plagued me for sometime. My 1990 Cadillac Deville is having starting problems. When this problem started I could get in the vehicle and turn the ignition switch and the car would not turn over. I hear the fuel pump prime and the relays under the dash engage; however it will not start. After allowing the car to sit for 20 min or so, I get back in and it cranks up with not problems. If I travel to my destination the problems happens again. Now, the problem has good worse it takes much longer now for it to start. A friend check the starter with a screwdriver and the car turned over, but the car still would not start from the switch. We concluded that the ignition switch was defective since everthing else was working properly; the fuel pump, relays and the starter. I changed the ignition switch and the problem persist. I did not change the key switch, and I discovered that the number 11 fuse keeps blowing. Do not know if this is related to the problem, but I thought you should know. If you need any further information about this problem, email me and let me know.
Avatar
Larry brevelle
July 20, 2008.



Its the pass system (security system )
the key has a resister in it and if the alarm module don’t read it then will not allow the starter to engage or the fuel injector open
most common an open wire inside the tilt wheel
area
have the resister in the key measured and u can buy the same at radio shake and install it in the wiring under the steering column

BMRFIXIT
Jul 20, 2008.


http://www.2carpros.com/forum/automotive_pictures/216199_1990_Cadillac_Key_1.jpg



This is a picture of the actual key. Is the black part in the middle of the chrome where the chip in is? My very first thought was the key being the problem; however, the design of this key does not look like most keys which has a bigger handle. The car does not have a keyless remote. THanks for your support, I will give it a try and let you know the results.

Tiny
Larry brevelle
Jul 21, 2008.


http://www.2carpros.com/forum/automotive_pictures/99387_casdi_1.jpg



this is the wiring diagram for the system notice the white wires .22 very small in diameter


http://www.2carpros.com/forum/automotive_pictures/99387_cadii_1.jpg



read more about the system and how its work
help you understand the system

PASS KEY
Resistor sensing contacts are located in ignition key lock cylinder. These contact the key resistor pellet on the key when it is inserted. When the lock is rotated, battery voltage is applied through fuse No. 17 to the pass key decoder module. The pellet resistance is then compared against the resistance value stored in module.
If key pellet is the proper resistance, terminal A3 is grounded, energizing the starter enable relay. At the same time, a signal is applied at terminal A2 to enable the Electronic Control Module (ECM). When this signal is received by ECM, it allows fuel injector pulses to begin.
If the key resistor pellet is the wrong value, the Pass Key Decoder module will shut down for 2-4 minutes. During this interval there will be no output at terminals A2 or A3.
If ignition switch is turned on again during this interval, the timer will begin over again and pass key decoder module will remain shut for another 2-4 minutes. The pass key decoder module will continue this process even if a key with the correct pellet is used to turn ignition back on. The timer is restarted by the ignition voltage at terminal A1 when ignition switch is turned to RUN position.
Once timer has completed its 2-4 minute cycle with the ignition switch off, the pass key decoder module and timer are reset. A key having the correct resistor pellet can then be used to start engine.
The SECURITY indicator is controlled directly by the Pass Key Decoder module. If pass key is actively preventing the vehicle from starting, this indicator will be grounded by the Pass Key Decoder module with the ignition switch in RUN, BULB TEST or START. When ignition switch is first placed in RUN, BULB TEST or START, the indicator lights for about 2 seconds as a bulb check.


BMRFIXIT
Jul 21, 2008.
This information is fantastic. I will follow every direction. Several last questions. The key is slightly bent, should I replace the switch and key so they both match? Will this help resolve the issue as well so that it will not happen again in the near future?

Thanks a million

Tiny
Larry brevelle
Jul 21, 2008.
Try another key 1st

BMRFIXIT
Jul 21, 2008.
The little white wire that you mentioned in another post is not broken; however, the plastic sleeve is damaged and the bare wire is exposed inside of the steering wheel. This may explain why the system is grounding out. Should I repair the wire? This site is awesome, I will be sending another donation in a few days, even if this issue is resolved.

Thanks!!


http://www.2carpros.com/forum/automotive_pictures/216199_cut_wire_2_2.jpg


Tiny
Larry brevelle
Jul 22, 2008.
This is very common with the tilt wheel
repair as needed

thank you !

BMRFIXIT
Jul 22, 2008.
From observation I believe this problem is common in tilt wheel because there is a brass piece close to these wires. When you tilt the wheel these brass parts eventually cut through the wiring. Because the piece is metal it grounds out when the key is turn or when the steering is turned causing the switch to malfunction. I also noticed that the plastic retainer that prohibits the wires from moving is broken and the wire are not in position so they get in the way of this brass object. Thank you very much I am still working!

Tiny
Larry brevelle
Jul 22, 2008.
My friend, problem cured. The key was bad. I went to the Caddilac dealer and when they put the key in the machine to get the pellet reading, they stated that it was unusual but the key had absolutely no signal. Because of this, I needed the vin number from the car so they could see what frequency the key needed to be, and from there they cut me another key. The key cost $30.50. I am being as detailed as possible so just like you wonderful people at 2carpros. Com I may be able to assist someone in further post. Thanks for all you have done, Cadillac " Back On The Road Again"! Smile! Look forward to the donation that I promised.

Signing Out!

Tiny
Larry brevelle
Jul 22, 2008.
Happy driving
and thank you !

BMRFIXIT
Jul 22, 2008.