I know I could replace the switch or keep messing with it and all the connectors but I would rather just do away with it and use a push button system. Do you know the sequence of which contacts get power or make a loop as the key rotates in the cylinder? If I know which ones to connect to switches I think it would be cool and different to have a push button. I have seen the following available also but am a little skeptical about them working perfectly:

http://www.ebay.com/itm/Smart-key-car-security-alarm-system-passive-keyless-entry-push-button-start-stop-/171859206225?hash=item28039b6051

 

The sequence is:
1= The key is inserted to the ignition switch, the resistor value is read and sent to the computer using the two external wires that wrap around the tumbler. The key also hits an internal SPDT switch that breaks a connection from the small black wire in position #8 (common) in the black connector to the small tan wire in position #9 (NO Key) in the black connector. It then connects the small black wire in position #8 to the small GREEN/BLACK wire in position #7 (Key In) in the white connector. This signal is sent to the computer.
2=Rotating the key to the ACC position connects the large BROWN wire in position #4 in the black connector to the large RED wire +12V feed in position #1 in the white connector, this turns on the ACC circuits.
3=Rotating the key to the IGN position connects the large ORANGE wire in position #3 in the white connector to the large RED wire (+12V feed) in position #6 in the black connector, this turns on the IGN RUN circuits. Also, the large PINK wire in position #5 in the black connector is connected to the large RED wire (+12V feed) in position #1 in the white connector, this turns on the IGN START circuits.
4=Rotating the key toward the start position first breaks the connection from both the large BROWN and ORANGE wires to the large RED (+12V feed) wires, this turns off both the ACC and IGN RUN circuits but the IGN START circuits remain on.
5=When the key is rotated into the START position, the large YELLOW/WHITE wire in position #2 in the white connector is connected to the large RED wire (+12V feed) in position #6 in the black connector. This turns on the starter relay coil and that turns on the starter.
6=When the engine starts and the key is released, an internal spring moves the key back to the IGN position. This turns off the starter by disconnecting the large YELLOW/WHITE wire from the large RED (+12V feed) wire. Both the large ORANGE and BROWN wires are reconnected to the large RED (+12V feed) wires which turn on the ACC and IGN RUN circuits.
7=As the key is turned to the ACC position, both the IGN RUN and IGN START circuits are turned off by breaking connections of the large ORANGE and PINK wires to the large RED (+12V feed) wires.
8=When the key is rotated to the OFF position the large BROWN wire is disconnected from the large RED (+12V feed) wire turning off the ACC circuits.
9= When the key is removed the resistance reader tells the computer that there is no resistance. The small black wire (common) is disconnected from the small GREEN/BLACK wire (KEY IN) and is connected to the small TAN wire (NO Key).
I might have the red wires mixed up as to what connector they are in but it doesn't matter since they both are +12V feeds in parallel.
The tricky part of converting a C5 to pushbutton start is simulating the key in/out signal and the door lock/unlock signals. They are set up to warn the driver so the keys don't get locked in the car.
The kit doesn't show how it's wired to the car, if the connectors in Bill's picture are removed to wire in the kit then the old ignition switch cannot be reinstalled if the kit ever fails.
Bill, I always wondered why the two red feed wires are each fused with a 60 amp fuse, it seems too large for the gage of wire and for the loads. I'm running two 20 amp fuses now.

 

I've had the symptoms and pulled my ignition switch to clean the contacts. (They were corroded, as is so often the case.) But this wire was broken when I opened up the dash panel. What do you guys suggest?

 

The silver can on the end of the ignition switch that the wires go to is the key resistor chip reader.... Yours is CUT!

Either some one has permenant resistors wired in or you cant start your car!

 

One of the best threads for any C5 electrical gremlin fix.

This along with the correct CCA battery would be the best 'Start' to any C5 electrical issue.

Bill is the man!!

 

Car: 2000 Convertible with all the options, only 35k miles, but usually driven long enough to warm-up the car/engine, so not 150k miles worth of stop/starts which should be the average mileage on a 15 year old car and minimum expectancy of the switch.

Issues: intermittent & erratic DIC messages (reduced power, low voltage, service ABS/Traction Control, etc) numerous DTCs (Ps, Cs, Bs, Us -- over 4+ months), frequent dim/flickering dash illumination when key moved to 'on' position, one complete shut-down (power loss) at a stop sign (which was after new battery and grounds cleaning which finally sent it to the dealer). However, whenever the engine was started without DIC messages, car/engine ran GREAT.

Owner's actions before switch replacement:

1. new battery (old one was 4 years old, and no indication of issues and resting battery voltage was near the new battery and charging voltages were normal/same as with new battery, but replaced just in case, new interstate Megatron II MT-78),
2. disconnected 4 forward frame rail grounds (disassembled both connectors per Bill's pictures from his other post on codes), cleaned, reinstalled (just used nail file and WD40) -- they seemed ok and likely not the problem, and were nothing like Bill's pictures, albeit the passenger side forward most frame rail nut did seem like it could have been a bit tighter.
3. Read & reviewed service manual extensively, cleared codes regularly looking for common reasons.
4. replaced IGN and FPMP relays (under hood, by battery) based on their chattering during some start-up testing and not hearing the Fuel Pump on quite a few start-ups (when key initially turned to 'on'). There was a slight build-up of oxidation on the relay contacts, but their Ohm resistance was near zero, so likely they were NOT the real problem, albeit there was a slight improvement at first, so worthy of replacement nonetheless.
5. Concluded it was most likely a power side problem and NOT a ground issue.
6. Finally took to dealer (car is daily driver in FL and 'mechanic' was out-of-town).

Dealer's 'corvette expert' action before switch replacement:

1. 2.5 days & $300 of 'alleged' daily diagnosis trying to recreate/find the problem, inclusive of removing right wheel and wheel well liner, and dangling PCM and TAC from their wire harness, and uncovering BCM (pulling back passenger foot well carpeting), and connecting a Tech II, getting history codes -- just apparently no real-time diagnosis - as if either limited ability or time or frequency of issue to perform real diagnosis.
2. 'gut' recommendation to replace the PCM (with a remanufactured unit which is all that's available now-a-days), bases mainly on the U1016H DTC which many modules reported (page 8-25 in 3-book, red cover, original GM Service Manual set defines U1016 as 'Loss of communications with PCM').
3. daily phone follow-up with one site visit too (felt was needed to assist/focus/assure progress). Found much less than anticipated focus on the car and true diagnosis being done.

Owner OVERRIDE of Dealer's 'recommendation' (you do NOT have to enact Dealer recommendations if you feel it will not correct the problem):

1. I was NOT convinced it was the PCM - based on the DTCs and my analysis and manual reading, especially coupled with the only limited dealer analysis and only a 'gut' based suggestion that the PCM was the problem, -- and especially given the car's engine ran perfectly when started without DIC msgs - and the same errors can occur when there is a loss of power to the PCM.
2. Therefore, we instead requested ignition switch be replaced ($150 part plus $120 labor) and DTCs cleared and car reassembled and with the caveat that IF the issues reoccur, then worst case is $250 wasted, and we would then consider replacing the PCM.
3. Dealer mechanic likely did NOT follow manual's recommended repair approach and failed to disconnect battery before replacing ignition switch -- leaving/causing 4 additional DTCs (B2578, U1016,64,96) as well as no loss of Radio Theft deterrant code nor radio channels. Also, upon picking up car, initially received very odd alarm with the driver's door open, as if key was left in the ignition -- this cleared-up after one complete start/stop cycle.

Results after car brought back home (during drive home, and 2-3 start/stop cycles, no more DIC msgs -- so, so far YAY). Then:


1. Cleared dealer left-over DTCs.
2. After 2 days, and over 15 start/stops -- NO more codes nor dash flickering nor DIC messages and car and engine are running perfectly.
3. confidence is car is restored.

THANK YOU Bill Curlee for your POST, your write up along with all the other member posts gave me the confidence to override the dealer with success.

Additional Thoughts for Bill Curlee and other forum members:


1. Ohm tests of the contacts does NOT tell the whole story. Based on our testing, even though the contacts tested as zero ohms, that was a static movement test. likely the ohm test should be conducted while the switch is being rotated (a bit difficult to do)-- or by disassembly and visible examination.
2. Upon disassembly of our old switch -- the following was discovered -- and using Bill Curlee's hand drawn electrical diagram (DSCF0055-2.jpg), and his DSCF0019-1.jpg picture of the inside of the switch's contact blocks and push-up pins (our switch looked much worse), I would be annotated our findings as follows:
3. follow Bill's recommendation of graduated sanding with a high polish finish and final mating scoring -- as electrical contacts are sometimes made of two metals (base and plated), both contacts must be flat or nearly flat and must align and mate correctly, and electricity likes to jump from a sharp-edge --- However, be cautious that the sanding does not remove a plating of metal over a base metal nor thin out the contacts pads, as thinner metal will heat up even more.
4. the re-bending of the switch contacts may need to consider that the 'timing' of each contact may be important -- so by over-bending or not bending consistently, it might cause the connections to occur out-of-time with each other / original design -- Also, albeit not yet disassembled, it is possible the little push-up pins that are controlled by the rotation of the key mechanism might wear on the underside and also affect timing.
5. 'new' ACDelco switch can be found for +/- $75 --- perhaps a better choice -- versus the time to clean an old one (albeit not as much fun or rewarding) -- especially given the likely change in metal from time/heat/cool cycles which cannot be undone by sanding.
6. Many DTCs happen when a situation occurs for just 5 seconds -- so it does NOT take that long for the switch to create a problem for one or more modules.

summary:

If you are chasing erratic DTCs, especially U1xxx errors, replace the ignition switch before any modules.

part number embossed on old switch confirmed it was likely the original switch. Nonetheless disappointing that although it was a 15 year-old switch, it had only 35k miles on it, with most trips being at least 20 miles (so NOT a excessive amount of start/stops), so that it would fail so miserably and at such a low mileage--- hum...

Also considering this switch is used in many GM cars, whereas it might work OK in other cars with less electronics -- as cars move more and more to having lots of onboard computers --- which are more sensitive to voltage drops and electrical interference due to poor contacts -- I foresee an increase in switch failures being diagnosed as the root cause of other issues.

 

Very NICE write up... adding this to C5 files. Thank you

 

My C5 has been doing the same thing for the last few months. Will start most of the time then will not crank at all but power to everything once in a while. Starter was changed when this started but same issue still. I guess a ignition switch is needed.

Thanks for the detailed write up

 

TO: 73Corvette & 8VETTE7,

Thank you for the compliments, I just hope it can help others (my way of pay-it-forward from Bill Curlee's write-ups).

To: Phantomvette,

Thank you for the compliments too.

Also, regarding your cranking issue, and considering the ignition switch activates the starter solenoid, it would make sense that your ignition switch is the problem --- although upon removal, the tumbler's key resistor wires should be checked to assure the key's resistance is being properly sensed - i.e. measure key resistance, then put key into tumbler and check resistance across tumbler wire connectors -- to assure the same resistance is being sensed to the connector and thereby prevent engagement of the ignition disable feature.

To All:

Our car continues to operate flawlessly. Further, the car seems to be driving better all the way around, as if the switch was creating other subtle issues.

Also, it appears that the bad switch may have been causing interference with cell phones/blue tooth headsets -- as we used to hear 'picketing' (sounded like person at home could hear the car going across expansion joints in the road), but that is now gone too.

So, I now recommend adding the Ignition Switch to your list of regular 'maintenance' items.

Based on our low mileage, it appears that mileage (i.e. start/stop cycles) are insufficient to estimate when to replace the switch.

Therefore, based on our experience, and my reading through other posts, I suggest replacing the ignition switch at either 36k miles or 7 years, whichever come first.

 

BIG Thanks !

 

2001 Z06 with 53K in a dry climate developed the following:

When key was turned to run, DIC would flash, a relay would quickly click near the BCM, and the car would turn over but not start.

If I waited, the DIC would stop flashing and the car would with start, or the dash would go dim and nothing would happen when the key was turned.

In the past few months I had occasionally noticed "Charging System Fault" and "remove key; wait 10 seconds" messages. The "remove key" message is related to the steering column lock, and related to re-start or low voltage issues and not the lock itself. I have since disabled the SCL by installing the LMC5 Module from Compliance Parts to remove the SCL from the variables.

Two weeks ago I had the car just up and quit. I was able to restart and get it home.

I removed and cleaned all of the grounds in the engine compartment. There are a number of them; some difficult to get to. None were compromised in any way. They were all clean and tight.

So next on the list was the ignition switch. I followed Bill Curlee's switch repair procedure. The only difference I found between my switch and the one he repaired was that in the ON position my switch did not activate terminals 3 and 5.

The switch checked out OK. When the contacts were closed, there were 0 ohms.

I took it apart anyway. Several of the contacts had various degrees of black on them (carbon deposit, I suppose). None were pitted. I sanded them all lightly with 1500 grit, cleaned them with alcohol, slightly bent the contact arms, and reassembled the switch.

The switch tested exactly like it did before. 0 ohms when the contacts were closed. So I didn't think the problem was probably the switch.

I put the switch back in the car, and everything is back to normal! Wait, what?

My conclusion is that either the accumulation on the contacts is enough to cause them to go intermittent, or simply the act of unplugging and plugging in the connectors reestablished connectivity.

Time will tell if the problem is solved or not.

 

Great write up! When turning the key to start the car and there is a slight delay once in a while could that be the ignition switch? I mean it's about a second, or half a second. When I turn the key and I'm about to say to myself wtf, whats going on, it turns over. The starter is not moving at all it's just dead for that short time. Thanks.

 

After all the diagnostics, I was told it was the theft control relay. Drove it home and same issue 2 weeks later. Back in and they found a wire harness under the dash plugged that they say should have been removed when they serviced the steering lock issue. I have not idea what harness it was but it was about 2 ft long with a good size plug at one end. We will see if that is really the issue or its the mechanics just guessing.

 

Hello to everyone. I'm a brand new member so just learning the ropes. Many thanks to Bill Curlee and the many contributors to the forum. Because of these posts I have: rebuilt my own ignition switch, cleaned all my chassis grounds, tested my TDR, verified all critical fuses, and checked the voltage on the four primary wires going into the TDR. I discovered the black/yellow wire does not go to ground when I roll the ignition to the start position so I forced it to ground with a separate wire. My vette starts every time and drives perfectly. My question to all you learned specialists is, what the heck do I do now? Permanently ground the wire? I've searched the posts but can't find anything on the subject. Again, many thanks to all.

 

That harness is GM's Ill-conceived answer to the column lock issue. It is sometimes the ROOT of column lock problems. If anyone has one, rip it out and install a LMC Column Lock Bypass.

If you THINK you can IGNORE the Column Lock Issue, You will sooner or later become close personal friends of Murphy when you least expect or desire to be.. TRUST ME! I've met him and we discussed this very issue!

Here is a picture of the GM Relay harness.

 

The YELLOW/BLACK wire is grounded by an electronic driver circuit inside the BCM. The BCM monitors the cars physical security and IF,,,, its happy that you are the OWNER of the car and all is well, and all the SECURITY LOGIC is good,, it allows that circuit to go to ground ; Thus allowing you to crank the engine when you have met the safety logic CLUTCH SWITCH depressed trans in N key in START.

Do your FOBS work?

Do your doors lock and unlock properly>

Can you use the KEY to lock and unlock the doors and set and unset the alarm??

Does your security system work properly??

If you lock the doors with the FOB (windows DOWN) and reach in and open the door/s ,,, Does the alarm go off???????????????

Same for the TRUNK/hatch..

OR


The BCM is not working properly (for that circuit)

Test out that security stuff.

 

Thank you so much for your guidance. The answer to all of your questions except one is 'yes'. If I lock the doors with the key, I can reach inside and unlock without setting off the alarm. The key does not appear to set the alarm. As an aside, the system has never set any codes.

 

I have the exact same problem as pictured, how did you solve this broken wire problem?

 

Thanks again Bill. I have an intermittent turn signal problem. Sometimes they just will not light up. I found that if I jiggle the key in the ignition they will start working. Thinking it may be a bad contact in the switch???

 

Dave

There is a TURN SIGNAL (Multifunction Switch) repair thread too!

- C5 Multifunction Switch repair - http://forums.corvetteforum.com/c5-t...f-replace.html


Give the switch a good tune up and make sure that you check the contact resistance before the repair and then again after.

Bill