Bobby Brewsky

I posted in the scan and tune section and only had one gentleman reply. I thought I might get some help here.

I used this print out (post #5) to attempt to diagnose my problem.
http://forums.corvetteforum.com/c4-g...lay-timer.html

After jumping terminals A to G, nothing happened per the directions. I then found out that the 1996 jump out is different...CRAP!!! I hope I didn't do any damage, will someone PLEASE CHIME IN?

On to the correct jump, Code C12. It appears that this isn't an issue through research. Following the directions from the above, 1.3 displayed in the trip monitor, then, ENG/MET until 03 is displayed, when the door is open, I read 0 as well as when the door is shut.

I am completely out of my element with electrical, my question is, do I replace the door ajar switch?

Source:
http://keenparts.com/pages/search.ph...x=0&submit.y=0


UPDATE:
I purchased the switch and installed, all the interior lights still stay on.

Going back to the procedure above, drivers door shut I read 0, I open the drivers door and it's still 0. I close the door and I get a 010 code now. Passenger door closed, I read 0, open the door I read 1, close the passenger door and I get the 010 code. In both instances, I can hear something cycle? I don't know what that is...

Can anyone help?

kg4fku

I can't open the link thread you are referring to so I am going to go out on a troubleshooting limb and start with the door switches.

1. Start with the motor running and the stereo playing. When you turn the key off, does the radio stay on?

2. If the radio stays on after the engine is shut off and you open either door does the radio turn off?

If the radio stays on in step one then the car believes the doors are shut. If the radio shuts off as soon as the ignition is turned off then the car believes the doors or door is open. This would indicate a bad door switch or something further up stream is broken.

If the radio stays shut off when both doors open then it is not the door switches. You will have to perform this step twice. Once per door.

Have you attempted to cycle (move to multiple positions multiple times) the interior light dimmer/toggle switch located on the headlight switch? Does it turn the interior lights on and off when it is cycled? Does it dim and brighten the dash lights? You may have to put your finger on the photoelectric eye to make the dash lights dim.

Bobby Brewsky

Answer: The '90-'96 Corvette courtesy lights are controlled by the CCM (central control module) located in the dash behind the radio receiver. The courtesy lights are set-up with a delay when entering or exiting the passenger compartment; The courtesy lights are also designed to turn off after ten minutes when the doors are left open to avoid battery drain. If the doors are opened and closed in the ten-minute time period, the timer starts all over again. Courtesy lights should not come on at any time when there is enough ambient light available to satisfy the light sensor in the dash. The light sensor is located in the DIC (driver information center) at the upper left corner. Courtesy light on input signals come from the door ajar switches, door lock key switches (when going from the locked position to unlocked), headlight switch (moving the instrument cluster dimmer switch to the top), and the ambient light sensor. Once the CCM gets a signal from a door lock key switch, it processes the info and then latches a courtesy light relay located behind the passenger side of the dash, but only if the ambient light sensor senses low-Iight conditions for illuminated entry. If the door was unlocked upon entering, the door ajar switches provide info to the CCM with- out involving the door lock switches. The ambient light sensors come into play after input from the door ajar and lock switches. After 1992, the PKf {passive keyless entry} system became involved with the courtesy light. The PKf signaled the CCM that the door was unlocked and the courtesy lights should be on in low ambient light conditions. Beware! This same situation may apply if an aftermarket alarm system was installed on a '90-'92 Corvette. If you have an aftermarket alarm system, check there first.

Now that we have an idea how the system works, let's see if we can figure out what's causing the problem. The first place to check is the CCM for possible codes relating to the problem. You can enter diagnostic mode by grounding terminal G to A in the ALDL {assembly line diagnostic link} connector under the driver-side dash panel. The ALDL points downward and is about where your right knee would be while seated in the driver seat. ALDL Terminal A is at the top right corner and terminal G the lower left corner. Use a jumper wire to connect terminals A to G, and then turn the ignition switch to the ON position. When the key is turned on, fault codes will be displayed automatically in the speedo LCD screen. The module number will be displayed in the left center of the LCD starting with mod- ule 1, which is CCM data. The next module displayed will be 4 fCM {engine control module} codes and finish with module 9 displaying ABS/ ASH {antilock brake system/acceleration slip regulator} and fBCM {electronic brake control module} codes. The codes will have an "H" for history codes and "C" for current codes, meaning the problem is occurring right at that moment. After any codes are displayed for a module, the screen will display ,,-- " ending that module interrogation and going on to the next module. If you miss the codes the first time, you can turn the ignition key off and then back to the on position and the codes will display again in the automatic sequence as long as the jumper wire is in place on the ALDL. There is also no limit to the number of times the codes are displayed.

Once you interrogate the CCM, you may find code 24, indicating a shorted courtesy light relay coil or CCM internal open circuit or code 25, which is a courtesy lamp relay coil circuit open or shorted to ground in the CCM. If you find a code, make note of it, then you can select the CCM cycle inputs function by repeat- edly pressing the TRIP/ODO button in the DIC until "1.3" is displayed in the trip monitor area of the speedo LCD screen after the automatic code sequence has finished. Once you're there, press the ENG/MET button until "04" is displayed in the odometer area of the LCD. This is the right door ajar input. If you pass "04," you can go back by pressing the FUEL INFO but- ton. When the door is opened, "I" should be displayed in the LCD odometer area and then "0" when the door is closed. If the door is open when you start interrogating the system, "I" will be displayed and then "0" when closed. After testing the right door ajar, go to "05" left door ajar and do the same test. This will tell you if the door switches are working properly; and if the CCM is processing the info correctly. If the correct info is displayed, the door switches, wiring, and CCM is processing the info correctly.

The most likely problem is a malfunctioning door lock key switch, especially if it's used often. There will be no code for this problem, but can be tested while performing the input tests. Go back to test 1103'1 in the input tests. A "0" should be displayed until the door key is inserted and turned to the unlock position. The display should be showing a "1" in the unlocked position then back to "0" when the key is centered in the door lock. If the display shows "1" all the time, you have found the problem. The door panel will require removal and door lock cylinder key switch replacement.

If that didn't fix the problem, the next step is to see if the courtesy lights can be controlled by the CCM manually; We can cycle the courtesy lights through the CCM output test. This tests the courtesy light relay operation, wiring from the CCM to the relay and wiring to the courtesy lights. Select the CCM cycle output function by pressing the TRIP/ODO button in the DIC until "1.4" is now displayed in the LCD screen. Once you're there, press the ENG/MET button until 1110'1 is dis- played in the odometer area of the LCD. If you pass "10," you can go back by pressing the FUEL INFO button. When 1110'1 is displayed, the courtesy lights should go on and off in approximately three-second intervals. If the courtesy lamps stay on during testing, I would check the relay under the passenger-side dash for possible sticking contacts. Remove the carpeted lower knee-bolster panel on the passenger side of the dash to access the relays.

The panel on the passenger side of the dash that houses the fuse panel must be removed to remove the lower knee- bolster panel. There is one tmm screw hidden behind the fuse panel bezel for the lower panel. The courtesy light relay would be the second relay from the passenger door side of the dash. There is a bank of five relays attached to a piece of plastic channel that runs parallel with the dash. Once the relay is pulled, the courtesy lights will be off unless the headlight switch is causing the problem. When the headlight
switch instrument dimmer rheostat is in the fully up position, the ground circuit to the courtesy lights is completed, bypassing all of the aforementioned components. All of this info gives you a good idea of what goes on and should point you in the right direction.

If the door ajar info was correct and pulling the relay turns the courtesy lights oft; try a relay. If the relay isn't the problem, the CCM is grounding the relays gray/black striped wire, which could mean CCM replacement. It's difficult to access the relay and even more difficult to check the wiring in the relay socket, but to know for sure that the CCM is the culprit, the gray/black wire would need to be checked for ground. There is a possibility the gray/black wire is shorted to ground between the CCM and courtesy light relay. If the gray/black wire is grounded all the time, the CCM would require access behind the A/C Controller and the radio. At this point, a factory service manual should be used to further test and access the CCM.

MAY 2006 CORVETTE FEVER

Bobby Brewsky

Yes

Yes, the radio shuts off when either door is open

Yes, it will turn on the interior lights and yes, it dims the instrument lights. This is reaching in through the window after the interior lights time out and turn off.

kg4fku

I get off work in a few hours. If you can wait until then and no one has helped you out, I will go out to my car (96 vert) and see what mine does with what you have provided from yours.

Can you tell me what switch you replaced?

Also, when did this start happening? Was it after you had something installed or repaired? Was it after the interior got wet? Basically, can you think of something that may have caused this situation? Sometimes it is easier to find a cause then look at a symptom.

Also, please include any other issues that might be related to this issue AND what steps you have completed in troubleshooting.

Bobby Brewsky

UPDATE:
My mistake , followed the procedure to 04, RH door reads 0 when closed, 1 when open, close the door and it reads code 010, lights stay on.

Followed the procedure to 05, LH door reads 0 when closed, 1 when open, close the door and it reads code 010, lights stay on.

Hooked on Vettes

Insert the door key in the driver side door lock cylinder and turn left and right then make sure when you remove the key it's pointed vertically before removing it.
If that doesn't work try the samething on the passenger door.

Bobby Brewsky

Thank you so very much for your help.

I replaced the door ajar switch on the drivers side near my left elbow when sitting in the drivers seat.

It happened a week ago, beautiful day, no issues whatsoever up until then.

The next procedure per the instructions is:
The most likely problem is a malfunctioning door lock key switch, especially if it's used often. There will be no code for this problem, but can be tested while performing the input tests. Go back to test 1103'1 in the input tests. A "0" should be displayed until the door key is inserted and turned to the unlock position. The display should be showing a "1" in the unlocked position then back to "0" when the key is centered in the door lock. If the display shows "1" all the time, you have found the problem. The door panel will require removal and door lock cylinder key switch replacement.

I'm so confused, I don't know what 1103'1 input test is?

Bobby Brewsky

I've done this to the drivers door before, just did it again, nothing, lights still on.

I've not done this to the passenger door, just did, nothing, lights still on.

I guess I've been focusing on the drivers door as I had not used the passenger door very often.

kg4fku

three possible issues here.

1. Door jamb switch is bad (driver or passenger)
2. Dimmer switch is bad (main headlight switch)
3. Computer is bad

I would start with the cheapest point first.

1. Unplug the driverside door jamb switch. If the interior light go out as normal then this is the issue. If not repeat on passenger side. The Door jamb switch provides a ground to the system when the door is in the open position completing the lighting circuit. I do not believe this is the issue as the radio turns off when the doors are opened but there could be a secondary set of contacts on the same switch that the diagram I have does not show.

2. Unplug the dimmer switch. If the lights stay off then this could be the issue. According to the diagram I have, the coutesy light switch also provides a separate ground to the lighting system.

3. The final one is the contol module. Not sure how this interats with the system as it is not in the manual I am using (HAYNES). I have not received my FSM so I can only speculate from here.

shakedown067

You also want to check the cargo hatch switch (turns on the lights when you open the hatch). Mine broke once and had to replace it. You should be able to just unplug it to see if the lights go out.

kg4fku

I didn't mention the hatch switch as I thought that switch only controlled the rear hatch lights. Does it light all of the interior lights as well? I have a convertible so I have no idea.

Bobby Brewsky

UPDATE:
Okay, I went to 1.4 displayed in DIC, then on to ENG/MET button til I came to 10 1. Interior lights on for 3 seconds, it automatically switches to 10 0, lights go off for 3 seconds, repeats.

kg4fku

"On to the correct jump, Code C12. It appears that this isn't an issue through research. Following the directions from the above, 1.3 displayed in the trip monitor, then, ENG/MET until 03 is displayed, when the door is open, I read 0 as well as when the door is shut."

What is the correct jumper position?




Is your PKE working properly?

Do the lights time out (turn off) after 10 seconds?

Bobby Brewsky

I unplugged the drivers door switch, lights still on.

I unplugged the passenger side, lights still on.

Bobby Brewsky

I found the hatch switch, pushed the switch, the lights went out...released it, the lights came on, pushed it again and the lights go out after about 10 seconds.

I replaced the rear hatch seal a couple of weeks ago...the switch doesn't appear to have any adjustment...the battery is now dead, hooked up the charger.

Very promising lead.

TBC!

I can't thank you all enough for helping me, you're the best!

Deepa

OK...I just went through this.

First off, when you're in diag mode for the doors, 010 is 0, 1, 0, etc...it stores the previous few 0's or 1's so you can see it change in case you can't watch the display as you are working on something.

With the car running, are your interior lights on?

With the car off, keys out of the car, do they stay on?

A few weeks ago, mine came on in my 91 while driving. I immediately checked my dimmer switch for being toggled and it wasnt. My lights stayed on at all times and would have definately killed the battery. I had a short in ckt 156 which is a white wire which leads to the door lights, map lights, hatch lights, footwell lights, etc. I had just put an aftermarket rear view mirror a year ago and the wires were pinched. It took a whole year and one big bump to make them ground out.

There is also a feature with the door key switches when you unlock a door manually, the lights come on. Make sure the key slots are in the correct up and down position, not any other way.

Have you tried pulling the relay from under the pass side hush panel and see if they go off? If they do, you problem is the CCM side of the lights...If they don't, your problem is a short to ground on the ckt 156 white wire.

Here is my link. Good luck. http://forums.corvetteforum.com/c4-t...always-on.html

Mike

kg4fku

Really hope that you found the issue. I didn't think to ask about the hatch switch as the diagram I have doesn't show that it would light all of the lights but rather only light the hatch lights. Keep us informed.

Bobby Brewsky

For my 1996, I found this:
http://www.corvettebuyers.com/c4vettes/codes.htm

I used Pins 4/12
I threw the PKE in a drawer and forgot about it. Yes, it worked when I got the car, I was used to my 1987 without and don't like the fob in my pocket...silly eh? No, the lights stayed on with the engine running, or stalled. They would time out after about 10 minutes, battery saving feature? or when I pulled the fuses.

You were absolutely right, I had replaced the rear hatch seal. I believe it wasn't allowing the actuator to compress the switch enough.

I believe this was my problem. I put two small washers under the switch and now the actuator compresses the switch enough to shut off the interior lights. The battery is now charged, everything re-assembled and it appears everything is working correctly.

I thank everyone who helped me out. I am soooo ignorant when it comes to electrical. I couldn't have done it without the support and patience of this forum and it's members.

I can usually follow instructions, but I have to be able to understand them. There is a certain sense of satisfaction and pride doing something myself, with your support of course.

I believe I owe it to the forum to become a supporting member because of the members that took the time and effort to hold my hand and guide me through my opportunity for a solution. I sent a PM to the forum to guide me through the process.

Thank you again to all!

Bobby Brewsky

Quick update:

I went back and revisited the washers (Band-Aid) I used for this fix. I discovered that the entire hatch solenoid/bracket assembly that the hatch ajar switch is mounted to was slotted up/down. I removed the washers and adjusted accordingly, all's well.