Courtesy light relay will not ground = no lights, computer ?

[Java Junkie]

2003 safari van, is 1-week new to me, problem: computer will not enable "courtesy lamp relay" to turn on interior lights relay. grey/blk wire, blue plug c2, pin A3 (at computer) will not "ground" to enable relay. gry/blk when manually grounded at computer plug enables relay, so "no broken wire", lights come on as expected. Have mitchell-on-demand "courtesy lamps circuit" pages, checked all wires in circuit, fuses, relays, checked bulbs. 12v+ on ORanGe-wire avail and enabled (live) on all other light circuits (including this one). computer: p/n 15063578, currently back in dash. remote locks and programming function (for locks anyway) working as per manual. After market alarm. After market anti-theft. No known remote start.

Van is

There are four "driver" IC's on the computer board that are the same part. I have googled to see if there is an off the shelf replacement like a 74HC00 standard part, but I cannot verify these ARE the part number listed.
I can do soldering and board repair IF I can buy the part locally. IF I know the generic part number for the IC's, I can trace the logic in and out and see if the chip is getting the right logic to enable the output, otherwise the chip is a black box. If I can get a full schematic of the computer (not a block diagram or mitchell wire harness diagram) that would help.

Already Tried:
cycle ignition, cycle door switches, plug/unplug computer, unplug light circuit fuse 3 (20A),
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hxxp://www.dieselplace.com/forum/archive/index.php/t-2634.html.

Discusses the same problem I am having and that it requires a software update.

quote:

" Finally called Tech Assistance ... informed of new software yet to be released on this concern. Case #698023.

VCI(?) software sent to correct condition. Reprogrammed with updated software ... all lamps operational "

report here too:
hxxp://www.gmcproblems.com/tsbs/Safari/2002/

hxxp://www.carcomplaints.com/GMC/Safari/2003/tsbs/
--last item, bottom of list.

Is it likely a whole series made it to the show room with bad software & interior lights not working, so it needs software update???
If my truck was in a collision with an animal, would they replace the computer (mounted over radio, loose)???

[LiftedAWDAstro]

I would pull one of the door switches out. They are 11 mm I think and just screw in. You can then ground the wire to the frame or door hinge. My bet is that they are dirty. My 2005 had a couple that were dirty and didn't make a ground circuit.

[Java Junkie]

But shouldn't the over-ride switch also turn them on??

BTW. Do the radio button light up and fade/bal/bass etc letters???

[LiftedAWDAstro]

Yeah the O/R button should light them up. There is also a turn-off feature for the auto headlights using the same dome o/r button. Try pressing that to get the headlights to shut off when it's dark out. Mine were acting funky a couple times until I played with the o/r switch a bit. They just started working after.

[Java Junkie]

What I need is the computer's schematic.
I can offer some compensation for copy charges or postage, but a scan or pdf is better.
Still worthy of some compensation for pressing "send".
Nudge-nudge, wink-wink...
Free download links of course would also be welcome and appreciated !!

Please help.

[LiftedAWDAstro]

If I had the FSM for the newer ones I would send you some pages. My 98 books are different enough - no auto headlights.

[LiftedAWDAstro]

Here are the schematics from my 1998 FSM's.

[Java Junkie]

Please tell me how the headlight over ride button sequence is done, i'd like to see if it works .

Thankyou for the diagrams, but they don't show inside BCM.

Turns out cpu is 100 pin, and might be texas instruments.
The cpu does have "(C) 1998 TI" on it, so, maybe.

Anyone see any patent numbers on these or in manuals for programming??

[LiftedAWDAstro]

The headlight override is done by pressing the button 4 times, in, out, in, out. The headlights should go out and the the chime should ding once.

[Java Junkie]

Nothing happened with pressing button in/out.
I think I read that feature is disabled in .

I may have made a break through in finding the 16221256 relay driver chip.
After days of googling and checking every link, and anti-virus tripping everytime I looked at okdatasheet,com site.
I believe the CA3262AE is the driver chip AND a pdf datasheet can actually be found in two places amongst 77-pages of links.

It might also be: 74HC167, 274H9801, PLB38621, but none of those turned up data sheets for me.
Mine has "274 H0120"
"274 Hxxxx" shows up on the chip under the upper number "16221256".
So "274 H0120" = 20th week of '01 (or 2001) mfg date of the IC. (manufacturers put a date code on all IC's made)
So my computer was not assembled until on/after 20th week of 2001, van is 2003.

It seems obsurd to think the software is flashed wrong as an explaination on why the lights don't work, and further by extension, that the vehicle or a series of vehicles left the plant not having this software and as such the interior lights on this batch never worked.
Not likely at all.
So a software flash is not it.
I met with a GM mechanic who says these can't be flashed.

******************
I'm still looking for any patent pages on this computer as they will describe software in micro-controller, it will name the micro-controller, and describe any features and communication protocols only the factory knows about.
******************

[Java Junkie]

Door switches:

The door "ajar" light never comes on, BUT, when the keys are left in the ignition and driver door is opened, the "keys reminder" chime pings.

I'm stumped !!

I checked every wire input to the computer.
Every door switch, dome over-ride, courtesy/dim switch.
I mapped & tested every relay from the driver chips.
Every CPU logic pin feeding each driver pin was scrutinized.
BUT, I know which pin input on the driver is respondsible for driving the relay, and if the pin is forced high (eeek!!) the relay triggers as it should. But the CPU never presents a high to the driver.
The driver chip is good.

](*,) ](*,) ](*,) ](*,) ](*,)

The CPU just doesn't want to turn on the driver chip.

Open to all suggestions......

If I replace my computer, do I HAVE TO have the dealer do something to it before I can plug it in & use it ???
Did this vehicle use VATS for anti-theft?

[Java Junkie]

Update:

I had a Tech2 check the BCM (and try a re-program), this is the result:
B2618 Passenger Compartment Dimming 2 Circuit High

I check the signal from the courtesy light switch to the BCM and it was good, however at the component level on the BCM two transistors seem to be blocking the signal from reaching the CPU.
When I have time I will figure out what the part numbers for these two transistors are, make a schematic and see if they are the likely cause and replace them if nessisary.
The BCM must see this signal unstuck for 100 consecutive cycles before it will return to functioning again.

In the mean time... I HAVE LIGHTS !!!
I created a "GLUE-LOGIC" circuit using a GAL22V10 chip.
It connects to the four doors, courtesy, and overide switch.
The 4 [doors] are NAND'ed together, AND'ed with the [overide], then OR'ed with the [courtesy].
Works great.

The existing voltage dividers only supplied enough current to drive the CPU inputs, so new voltage dividers were added to each input.
[switch]------/\/\/\/-----[4.1V]-----/\/\/\/----[ground]
[+12/gnd]----[39K]----[toINPUT]---[20K]----[ground]
Each branch draws 200uA, 1.2mA total consumption. That's reasonable.
The CPU's output to relay driver pin was desoldered so the GAL's OR output could drive the driver chip input directly without conflict.

This is my final version:

Whatcha' think??

[Drummernaut]

Great Work! Nice job on keeping the amps low.