Cadillac Seville / Cadillac Eldorado Forum Discussion, Starting disabled randomly - wait 3 min in Past Cadillac Vehicle Discussion; I'm having random instances of anti-theft starting disable. Started about 3 weeks ago and has happened 4 times since. Never ...
I'm having random instances of anti-theft starting disable. Started about 3 weeks ago and has happened 4 times since. Never saw it before it happened the first time. Thought maybe my original key chip was weak or the key was becoming worn so I switched to my spare and it just happened again. Don't know where to look in the FSM so I thought I'd post and gather your thoughts! Thanks
Your car has a built-in Diagnostic Trouble Code system. use the proper procedures in the sticky post ^^^ "How to pull codes". The security system will set any of a couple dozen codes, and the definitions are in the sticky - in the link with "obd2" in the address. Pull the codes and post them and the definitions here.
Sub, Pulled codes, I know that procedure intimately. Started car with each key and then pulled codes with each key in turn, heres what I found;
B2710H - Passkey II open shorted key pellet before good
B2780H - Passkey II wrong resistor value before good
Found circut description but can't find diagnostic location in FSM
Look at the base of the key base, you will see a black plastic with a metal thing sticking from the middle. This is on the both sides of the key blade.
That is the pellet VAT resistor and the 2 metal tabs in the middle of the plastic are the contacts. If you get a ohmmeter and measure the resistance from one side to another of the key blade on these 2 contact tabs you will get your VAT resistance. There are 15 standard values and you should have one of the following:
1) .402 KOhm (.386KOhm-.438KOhm)
2) .523 KOhm (.502 KOhm -.564 KOhm)
3) .681 KOhm (.650 KOhm -.728 KOhm)
4) .887 KOhm (.850 KOhm -.942 KOhm)
5) 1.130 KOhm (1.085 KOhm -1.195 KOhm)
6) 1.470 KOhm (1.411 KOhm -1.549 KOhm)
7) 1.870 KOhm (1.795 KOhm -1.965 KOhm)
8) 2.370 KOhm (2.275 KOhm -2.485 KOhm)
9) 3.010 KOhm (2.890 KOhm -3.150 KOhm)
10) 3.740 Kohm (3.590 KOhm -3.910 KOhm)
11) 4.750 KOhm (4.560 KOhm -4.960 KOhm)
12) 6.040 KOhm (5.798 KOhm -6.302 KOhm)
13) 7.500 KOhm (7.200 KOhm -7.820 KOhm)
14) 9.530 KOhm (9.149 KOhm -9.931 KOhm)
15) 11.800 KOhm (11.320 KOhm -12.290 KOhm)
So for example if you have between 5.789 KOhm and 6.302 KOhm then your key are VAT 12.
Now when you stick your key into the ignition cylinder there are 2 contacts inside the cylinder that touch the 2 tabs of your key and that’s how the car knows if the correct key was inserted. The key must be correct mechanically (i.e. the blade pattern must match the tumblers) and electrically (i.e. the VAT value must match).
Here is the diagram of the circuit from the ignition cylinder to the IPC. As you see is super simple, 2 wires going from IPC (Pin A10 and B10) from C1 connector to the Ignition Cylinder contacts. Right in the middle there is a C202 connector (pin E12 and E13). The C202 connector is the big rectangle connector underneath the steering column visible once the driver’s side kick panel is removed. The VAT wires are easily recognized because are the thinnest wires in the whole harness.
I already included on the diagram how you should bypass the system until you find the issue.
The weak points in the circuit are:
1. The key, the resistor may fall off (pretty obvious to notice)
2. The contacts inside the lock cylinder, in time they ware out not making good contact with the key pellet anymore (starts with occasional “Wait 3 minutes” messages).
3. The thin wires between the ignition cylinder and the C202 connector (especially if you tilt the steering column often).
4. The contacts inside the C202 connector (especially if somebody serviced recently the vehicle in that area)
No matter what you do DO NOT CUT ANY WIRE. You can follow my instructions to install a temporary bypass at the IPC connector (C1 is the middle connector). You will remove the 2 wires out of the C1 connector (Pin A10 and B10) using a needle or a paper clip inserted in the rectangular hole near each pin to release the wire out of the plastic connector. Then install a resistor with 2 leads soldered ending with the same pins so you can insert into the plastic connector (source the leads from a junkyard). Or option 2 is to install the bypass resistor to the C202 connector (same thing, remove the pins from the connector and install your bypass (with appropriate pins).
Now you have time to do the 1-4 diagnose steps.
N* Great HOW TO! I just have 1 question, all the rest is very simple, what resistor value should I use? I'm assuming I match the resistance of my key pellet. Is my assumption correct? Thanks a bunch. Love my ETC but it drives me nuts with the little bugs. Prefer old school. ( air, fuel, spark, set the points with a matchpack, and down the road you go. Remember those?) VATS #8 2.36KOhms on new key, also 2.36 on original factory key. 125K and climbing on the odometer, suspect contacts in ignition are worn. Engine has been in and out 3 times this winter but IPC plugs should not have been disturbed.
Like MoistCabbage said, match the value you get by measuring the pellet in the key (side to side). If is 2.36KOhm you can use a resistor between 2.275 KOhm -2.485 KOhm (but as close as possible to 2.37Kohm).
Hi, did the resistor fix at the C202 connector. Replaced the pins where they come in from the ignition side with pins that have a 2.36 Kohm resistor soldered on. Still get the b2711 code after the resistor fix. the other codes cleared and didn't come back. B2711 is PASSkey open/shorted pellet after good key. still have the "Theft system problem car may not restart" message. Had been driving like this for 3 weeks before I got the resistor installed, just never removed the key. Now there is no way for the computer to see the pellet, just the resistor. Have I missed something?
In my diagram I clearly recommend to install the resistor at IPC connector C1 (pins A10 and B10) NOT the C202 connector.
I don't understand why people bother with C202 connector (everybody rather go there), when the connector is half way between the wires (your failure may be between C202 and IPC C1 connector) and is easier to get to C1 IPC connector than to C202. All you need to do is remove the dash pad cover and is right there in a very easy and comfortable position).
I guess is all the movies people see with somebody doing something underneath the steering wheel column. In reality the average person doesn’t look anywhere near the same like the guy in the movie nor do the repair happens there.
N* I understood where You wanted me to install the resistor but my dashpad is warped to the point where if removed it may not be able to be reinstalled. 10 min to remove the pins at C202 and install resistor pins. Very easy to access and service. If the idea was to insert the resistor between the ignition and IPC I didn't see the difference other then sourcing and paying for a new dash pad. Do you have any idea what else I might look at to correct the B2711 current code? Thanks for your How-to and appreciate any furthur input you may have.
This really doesn't need to be such a procedure and I don't know where this "dont cut any wire" rule came from. There is an orange wire with 2 small white wires in it going up to the column. Those are the 2 wires that need to be jumped (soldered only) without taking the whole dash apart. And it is permanent. Done it 1,000,000 times.
Because you may cut the wire that has no issue.
I don't get it why would you cut wires when you can easily remove it from connector. Next time you change your mind you just put it back.
But after all is your car...
The dash is only 7 easily accessible screws away, it is mounted on a plastic substrate, so what ever you see wrinkled is just the top, underneath base is nice and fine.
I remember little over a year ago I was helping some CF member with his dimming mirror issue (not un-dimming while in reverse). After I explained what wires to check and so on all he understood was if I cut the reverse wire from the mirror harness my issue is fixed. I was so regretting I got involved into that, instead of checking what’s wrong with the signal he just cut the wire.
As for the OP, you do know the IPC can tell you what resistor is reading (well is a conversion from 10 to 255, where the lower the value the smaller the VAT). There are better way to diagnose cars in our days, not just go disabling stuff. The VAT system is actually pretty simple, 2 wires and a resistor.