|
this is what the FAQ says:
********************************************************
ABS Diagnostic Code Retrieval. [Tip from Tom Irwin] To retrieve any ABS diagnostic codes which are stored and are noted by a lit "ABS" lamp, turn the ignition switch on to KPII and leave the engine off.
Put the Diagnostic Link Connector (driver's side strut tower, same as ignition and fuel injection diagnostic unit) probe into DLC, Position 3. Push button on DLC for >1sec. and capture codes flashing in the red lamp.
To clear codes, place the DLC probe into position 3. Hold DLC button down for >5secs. Release for 3 secs, then press again for >5 secs. This will clear the codes.
The codes are shown in the table below. Note that these are generic; your car may not have two rear wheel sensors and thus the code will not apply
********************************************************
this is what ChrisH says:
************************************************************
What it is, is the black boxes (sometimes one gray) that are mounted to the left side strut tower towards the rear of the engine compartment. They will tell you everything you need to know, and the test lead is already installed. Read through the FAQ again, or buy a Haynes manual at least, and look into it farther.
It is a very sophisticated sounding term for a very simple setup. Something that implied that it actually put out codes would be more appropriate, but apparently Volvo took a hint from another manufacturer quite some time ago in calling it that.
Plus, you have DTCs which is "diagnostic trouble codes".
Ooh la la. DTCs.
So, knowing that, go out, plug in the DLC, and pull out the DTCs. Or plug the wire into the diagnostic box and get the codes. WHatever sounds more friendly.
**********************************************************************
Again, the car us a 1992 Volvo 740, 125k miles.
OK,
so I found the DLCs (I always wondered what those two boxes were).
One is black, one is grey.
The black DLC has three connections in it, #3, #2, and #6. It also has the test lead attached.
The grey DLC has only one connection in it, #3.
I did the procedure as described in the faq on the black DLC. The LED would turn on when I gave it the >1sec push, but then *nothing*. No Codes. Leads #2, and #6 both returned codes 1-1-1 (no problem), so I suppose my ignition and fuel injection systems are OK.
Interestingly, #3 in the *grey* box (the one with only one connector) returned 1-2-2, which if it *is* the correct ABS test point, would mean "Right side front wheel sensor: faulty signal at speed less than 40km/h"
But according to the FAQ, it should be lead #3 in the black box, yes?
Also, just in case the grey box #3 lead is the correct one, I tried clearing the code with the >5sec wait 3sec >5sec sequence, but the code would not clear out.
Other things I tried:
I pulled the 10amp fuse out of the relay under the dash, and the light remained on. The fuse is good.
I pulled the main wiring connector out of the head unit on the passenger side fender, and the light becomes nonfunctional. I have two good 12volt feeds going on that big power connector at the fat red wires, and a lesser (maybe 2 volts?) on a different wire.
I pulled and tapped on all the relays, to no effect.
Could it be that the grey box #3 lead is the correct one, and I just have a front right side sensor problem, or is the ECM part of the ABS system possibly dead?
|
