Air Bag Light - '93

OK, here's a good one. Just got the LX back from the body shop (more front end body work) and now the air bag light is blinking. However, there's a catch. It only blinks when I'm not giving it gas. If it's idling, cruising, or decelerating, it blinks. If I accelerate, it stops.

My first guess is something vacuum-related. Any ideas? TIA.

Joe Calypso Green '93 5.0 LX AOD hatch with a few goodies Black '03 Dakota 5.9 R/T CC

Reply to
Joe
Loading thread data ...

my god ya are a foctard scan for codes ya prolly lost a sensor

a vacume computer LMFAO foctard

h u r c a s t

Reply to
relic896

I don't see how the Supplemental Air Bag system could be vacuum related. It's all pretty much electrics and mechanics. With front end body work recently done, I'd check around the right/center/left crash sensors and associated wiring and harness connectors. The RH and LH sensors are located at their respective sides of the upper radiator support, behind the headlamps and the center sensor at the middle upper radiator support...

-- Mike

93 Cobra
Reply to
Mike R

snipped-for-privacy@verizon.net (Mike R) wrote in news:svt-cobra-1006052344390001@192.168.0.102:

I thought as much, but I wonder why it stops blinking when I give it gas..

I will certainly do that. Thanks for the tip, Mike.

Joe Calypso Green '93 5.0 LX AOD hatch with a few goodies Black '03 Dakota 5.9 R/T CC

Reply to
Joe

Joe, are you having battery charging issues of late??? The diagnostic monitor may be flashing a code 12 for low battery. This might also explain reving of the engine causing the lamp to extinguish. Make sense??? Maybe a bad regulator or alternator. Also, if you haven't done so yet, check fuse #7 (15amp).

-- Mike

93 Cobra
Reply to
Mike R

snipped-for-privacy@verizon.net (Mike R) wrote in news:svt-cobra-1106051842120001@192.168.0.102:

Yes, in fact, I am having battery charging issues. The underdrives on the car are killing the battery - at idle it's constantly discharging. Forget about it if the a/c or lights are on.

The alternator (stock replacement) is only about 18 months old give or take, and the battery is less than a year. Since I bought the car (I'm the original owner) I've never ever seen the air bag light go on except for start up and key-on-engine-off. The bag has never popped, either.

So does the air-bag light flash codes? I've never heard of that. But the discharging is certainly an issue. Again, thanks for the tip. All good stuff to check out.

Joe Calypso Green '93 5.0 LX AOD hatch with a few goodies Black '03 Dakota 5.9 R/T CC

Reply to
Joe

Yeah, the Diagnostic Monitor will display a DTC representing a two digit number when detecting a fault. No memory mind you after the key is turned off. You got to do it on the fly. So, for instance DTC 12 (low battery voltage) would be:

Flash (one second pause) - flash flash (three second pause) and then it repeats.

This particular code caught my attention after thinking about your original post. More so now than the front crash sensors with recent body work, but don't count those out. Right now, it's important to pull the code to narrow this down. The D/M monitors (among other things) battery voltage via fuse # 7. Don't forget to check this fuse. If it's blown, we need to figure why. If you have a voltmeter, measure the battery directly while the engine idles vs reving and note any voltage swing. Obviously, you've got a charging problem here. BTW, anything lower than 9 volts will trigger the D/M to flash a DTC 12.

It certainly is. Fix that first and maybe the air bag issue will resolve itself.

Yep, good luck with it...

Mike

93 Cobra
Reply to
Mike R
[posted and mailed]

snipped-for-privacy@verizon.net (Mike R) wrote in news:svt-cobra-1106052142280001@192.168.0.102:

Mike, you know it never occurred to me that the air bag light was actually displaying a code by blinking. Now I'll have to go check it out and see what it's telling me. And I will check the fuses as well. Again, thanks very much.

BTW, is there a web site or something that contains all the codes and what they mean?

Joe Calypso Green '93 5.0 LX AOD hatch with a few goodies Black '03 Dakota 5.9 R/T CC

Reply to
Joe

I just found this:

formatting link
If you're interested in a schematic:

formatting link
FYI. The D/M monitors battery voltage at pin 13 via fuse #7

Time for some coffee...HTH

-- Mike

93 Cobra
Reply to
Mike R

snipped-for-privacy@verizon.net (Mike R) wrote in news:svt-cobra-1206050956420001@192.168.0.102:

Great stuff, Mike - thanks! It's all in the archives now...

Joe Calypso Green '93 5.0 LX AOD hatch with a few goodies Black '03 Dakota 5.9 R/T CC

Reply to
Joe

directly

Mike, it's throwing code 51 which is 'Diagnostic monitor internal thermal fuse open'. Fuse # 7 is good, btw.

Here's the excerpt from one of the links you posted: "If the AIR BAG readiness lamp is flashing a Fault Code 51 and a short to ground has not been serviced, this means that an intermittent short to ground exists in the air bag system. The diagnostic monitor will eventually have to be replaced but only after a visual inspection leads to the repair of a short to ground in the wiring harness."

At this point, my question is: After I find and fix the short to ground, do I have to replace the diagnostic monitor? If so, where is it?

Joe Calypso Green '93 5.0 LX AOD hatch with a few goodies Black '03 Dakota 5.9 R/T CC

Reply to
Joe

Yes, you have to find the short to ground before replacing the D/M, otherwise you risk the chance of destroying the replacement. Code 51 is actually indicating the internal fuse is blown and the short to ground is not present. If the intermittent short returns, the D/M will flash a code

  1. The sequence of events for code 51 is something like this:

Short to ground-->D/M flashes code 13 and sends signal blowing internal fuse preventing unwanted air bag deployment-->D/M continues flashing code 13 while short is present-->short temporarily clears-->D/M now flashes code

51-->short to ground returns-->D/M flashes code 13 and so on....

Looks like you might want to continue inspecting the three crash sensors and associated wiring in the engine compartment. Sounds like there may be an intermittent pinched wire against body sheetmetal somewhere. Also keep monitoring the indicator to see if code 13 surfaces. And lastly, the D/M is located behind the lower center instrument panal...

-- Mike

93 Cobra
Reply to
Mike R

snipped-for-privacy@verizon.net (Mike R) wrote in news:svt-cobra-1406050854270001@192.168.0.102:

Mike,

After reading the links and your post, I now see what's happening. I've been keeping an eye on the air bag light, and it never reverts back to a code 13 - it's always 51. I've gone in there and checked around all 3 crash sensors and everything seems fine. Haven't seen any exposed or pinched wiring at all.

Because the intermittent short has never returned, I'm wondering if the shop somehow shorted out the wiring during reassembly (IOW, the battery was connected at some point during reassembly). Would that explain why (a) the DM blew in the first place and (b) why it's not throwing code

13?

I've also heard that the DM could simply go bad without experiencing an actual short. True? Theoretically, if the new replacement unit doesn't see another intermittent short, it will be fine, correct?

Finally, is the DM down behind the radio near the console or up in where the air ducts go? IOW, will I have to disassemble part of the dash to get to it, or can I just remove the center console that houses the radio and HVAC controls?

Thanks again for all your invaluable help!

Joe Calypso Green '93 5.0 LX AOD hatch with a few goodies Black '03 Dakota 5.9 R/T CC

Reply to
Joe

Yes, but the question is whether the short to ground has cleared completely and whether you risk blowing another DM replacement. You might want to call the dealer parts department and get a cost figure.

From what I've read, yes and yes.

Behind the radio (possibly lower). I'd try removing the glove compartment box and look inside to the left for a rectangular box with two harness connectors attached. Just to be on the safe side, PLEASE USE CAUTION and disconnect the battery first. The back up power supply should be disarmed with the internal fuse blown, but why take the chance. Disconnecting the battery and waiting a few minutes should also discharge the back up. Play it safe Joe. I'm only going by Helms, not from personal experience..

-- Mike

93 Cobra
Reply to
Mike R

snipped-for-privacy@verizon.net (Mike R) wrote in news:svt-cobra-1406051242290001@192.168.0.102:

Already did that today - it's $217 from the dealer.

So if I never see a code 13 after examining the wiring for shorts or crimps, I'll assume that I can put a new DM in without problems.

Without a doubt. Before I do anything the battery will have been disconnected for a few hours.

Mike, does Helms say anything about the size of the screws securing the DM? I'll bet they're torx bits too...

Joe Calypso Green '93 5.0 LX AOD hatch with a few goodies Black '03 Dakota 5.9 R/T CC

Reply to
Joe

Wonder if a salvage yard would sell you one.

If there's a $217.00 guarantee to never...

Here's a better description on location and removal:

Diagnostic Monitor Removal

1) Disconnect positive battery cable. 2) Remove radio. Diagnostic module is the blue box w/two connectors mounted below the climate control head. 3) Disconnect diagnostic monitor connectors. 4) Remove screws retaining diagnostic monitor and braket assy to instrument panal brace and remove assy.

The screws look like hex heads. Possibly phillips hex. They say four required, but I only see two locations in the drawing. Looks straight forward as long as Murphy's not looking over your shoulder :-0

-- Mike

93 Cobra
Reply to
Mike R

snipped-for-privacy@verizon.net (Mike R) wrote in news:svt-cobra-

1406051400330001@192.168.0.102:

goodies

late???

replacement.

Sounds

happening.

I've already e-mailed Tim (Musttanguy).

LOL! Well, if I don't see the code 13 again, I'm going for it.

straight

Cool. Thanks for the removal instructions. I'll let you know about Murphy when I tackle the job.

Joe Calypso Green '93 5.0 LX AOD hatch with a few goodies Black '03 Dakota 5.9 R/T CC

Reply to
Joe

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.