Air bag warning light

[GordonC]

Hi all, I have a NT auto, done about 220kms and the air-bag light has appeared on the speedo display for no apparent reason; I simply started it up one morning and it was there, and has been there for about a week now. I have done nothing out of the ordinary, and the airbag recalls were done a few years ago. Any ideas?

[erad]

I cannot comment on the NT model Pajero, but my NL Pajero had the SRS Airbag light come on. I tried to trace the fault myself but eventually took it to a guy with a scanner. He came up with a code which said faulty power supply. He then started checking all the fuses and found the fuse for the reversing light was blown. He replaced it and everything was good - until I got home and the fuse had blown again. Eventually, I found a short circuit to earth on the reversing light switch, and replaced it - no more problems with reversing lights or the SRS.

Why the SRS was connected to the reversing lights, I don't know. My Haynes workshop manual wiring diagrams were utterly useless. I eventually concluded that the designers chose a convenient power source for the SRS system. Maybe they still do it with the NT model??? Check to see if your reversing lights are working. If they are out, look for a defect in the wiring and then if all else fails, look at the reversing light switch itself - if you can find it.

[craka]

From memory of reading post on hear, I believe the hazzard light fuse can cause erroneous warnings lights to come on.

Also I believe there is airbag connectors under at least the front seats, check that they havn't come loose or been disconnected somehow.

[GordonC]

Thanks for the suggestions gents. I haven't had much time yet to spend on it, but of the easier suggestions, the hazard lights and reversing lights are functioning normally. When I get some spare time during daylight, maybe on the weekend, I'll look further into connections under the seat etc.

Hopefully it doesn't end up at the Mitsubishi dealer and a couple of hundred dollars later to be told "dunno".

[erad]

My Max Ellery W/S manual shows a diagram for the SRS system. It has a 3 fuses in the junction box (wherever that is) - one a red wire going via Fusible link 1 directly to the diagnostics connector and the other 2 (Black/White and Black/yellow) wires going to the SRS ECU via the ignition switch. The ECU has inputs from the following:

LH Side airbag module (Y-R; Y-Gr wiring)
RH Side airbag module (Y; Y-Bk wiring)
Side impact sensor (R/H) (Bk-R;W-R wiring)
Side impact sensor (L/H) (Bk-Bl; W-Bl wiring)
L/H front Impact sensor (Bk-Bl; W-Bl wiring **)
R/H front Impact sensor (Bk-R; W-R wiring)
L/H front airbag module (Y-R; Y-Gr wiring)
R/H front airbag module (Y; Y-Bk wiring to the clock spring, Y-Bl and Y-r after the clock spring)
** the wire colours are taken directly from my W/s manual and I think it is one of many mistakes

There is no reference to seat airbags in this diagram either.

The last one (R/H front airbag module ) goes via the clock spring in the steering wheel. The power for this system comes via a fusible link and not off the reversing light as per my NL model. If any of these have a crook connection, you will get an SRS light coming up. If you want my guess, I would try the clock spring.

I find it difficult to load copies onto this site, but if you want to message me, I can copy the page and email it to you (copywrite restrictions etc)

[GordonC]

Many thanks for your comments. I have just sent you a private comment with my email

[GordonC]

I think that the problem is solved (touch wood!) although I don't have a definitive answer for you all.

I took it to a local trusted mechanic who plugged in his scan tool and a heap of error messages came up, including one relating to low voltage. He said low voltage will definitely throw the air-bag into a tiz. However, it was about six months or so earlier that I replaced the battery, so it didn't make much sense that it only caused a problem now.

The only other thing he could suggest is that many cars, regardless of make, can start to malfunction in all sorts of ways, including completely failing to operate, if there is an excessive accumulation of old, probably not relevant, error messages. So he cleared out all the old data, and said come back a week later to see if there are any error codes that are repeating, thereby giving him something to work on. I came back a week later as requested, and there were no error codes in the system.

That was quite a few weeks ago now, and no further air bag warning light problems.

Problem seems to have gone away, but no real answers.

Cheers all, sorry I couldn't really help if any of you have had this problem

[erad]

GordonC: I had an SRS code come up on my NW, along with a couple of others. I had just bought an ICarsoft HMNIIcode reader/clearer. The HNMII cleared most of the codes, but from memory, would not clear the SRS codes. I had the low voltage code and that could not be cleared, so I took the beast down to the local dealer who used the MUTT system to clear the codes I couldn't get rid of. From memory, the SRS code still didn't clear, but every time I turn the ignition on, the SRS light goes out as normal. I don't intend to go hitting anything anyway, and if I do, hopefully the impact won't be enough to activate the SRS system.

I have just had a very flat battery, so I guess that the Low Voltage code is there now, and maybe the SRS light as well. It is too cold for me to go out and find out. I charged the battery and drove it 100 km or so and there were no abnormal lights so I guess it is all OK.

[Larppanen]

There is a recall for both front air bags "blow-up unit" (or something like that) replacement, are those done for your car already? Dunno can they throw codes, but just a thought as mine was done couple of months ago.

Recall codes are:
R30307 driver side
R30334 passenger side