Diagnostic Connector

[sumguy67]

I'm dealing with ABS issues.....

 

To check the trouble codes, the Chilton manual (pgs 9-24 &9-25) tells me to ground the check terminal while the engine is running.

Problem is that the book illustrates a 6 pin connector with one empty. It's not the same as my connector on my '95.

I've done the grounding trick on other vehicles and it works well.

 

Has anyone tried this?

Anything I've read online suggests that you have to go to the ECU (under the pass seat) for codes.

 

Thanks

[silverton]

Checking engine codes is from the ECU.

 

I'm also curious as to how to check ABS codes, my light is on and I would figure out how to fix whatever is wrong without throwing money at it.

[5523Pathfinder]

Checking ABS and ECU codes are completely different. ECU codes can be checked at the ECU. ABS codes must be checked after drivuing and still have the engine running. There is a Blue(should be) connector under the left side of the dash near the fuse panel. This the connector you need to ground to get codes. If you have the FSM or any manual, it should tell you exactly what pin to ground. Once you ground it, the light will flash on the dash. I will try and copy the procedure from Alldata....

[5523Pathfinder]

Here you go...

 

[sumguy67]

Checking ABS and ECU codes are completely different. ECU codes can be checked at the ECU. ABS codes must be checked after drivuing and still have the engine running. There is a Blue(should be) connector under the left side of the dash near the fuse panel. This the connector you need to ground to get codes. If you have the FSM or any manual, it should tell you exactly what pin to ground. Once you ground it, the light will flash on the dash. I will try and copy the procedure from Alldata....

 

This is what I figured, but I didn't want to make any assumptions..... thanks for verifying this. :-)

I guess I will have to dig around more to find the proper connector.

 

I have the procedure in the manual.... just sorting out the plug.

[sumguy67]

Here you go...

 

 

Thanks for adding this. It's just like my manual.

It's where I stopped because the connector was different.

I guess I have to find the right connector.

[adamzan]

Derek is there instruction as to how to reset the abs light if you had a problem but corrected it?

[5523Pathfinder]

If you have repaired your problem, the next key cycle should clear the code. This is why you have to perform this test with the engine running, perferably after you have driven it a few minutes. The ABS system tests itself upon every startup. Then, as you drive, it tests itself and the signals coming into it. If the light does not go out, you probably have a "hard" failure.

[adamzan]

Yeah what happened was is I swapped third members, but forgot to plug in the abs sensor. So I plugged it in but the light never went out. I guess the sensor in the third could be bad but it looks like a pain to swap.

[5523Pathfinder]

ITs actually pretty easy. Disconnect the driveline, pull the pinion nut, pull the pinion flange, unbolt sensor and pull it out. You may have to replace the seal also.

 

You could also hook up a DVOM to the sensor and test the sensor. You would have to ge the tires off the ground, put it in neutral, and give the rear wheels a spin. The meter should show a spike then drop as you rotate. I guess you could do the same with a analog meter now that I think about it. Basicly the same procedure as testing a speed sensor, cause thats all it really is.

Edited April 28, 2010 by 5523Pathfinder

[sumguy67]

After digging again and removing some plastic I finally found the correct plug (white in picture)

 

 

So I ran the vehicle for about 5 min over 40 kph and grounded the test plug.

No code flash, trouble lights just stayed on.

Now the fun begins..... I'll start with crawling under and checking visually.

Then pull the real wheels to look for more obvious stuff.

 

If it turns into a control unit issue ($$$) then this truck may become a non-ABS Pathy.

Edited April 28, 2010 by sumguy67

[5523Pathfinder]

Did you keep it grounded, or take it off? I usually keep it grounded until the light flashes.

 

 

That was the right plug. Now when I click on the picture, it show a VIN sticker!

Edited April 28, 2010 by 5523Pathfinder

[sumguy67]

Did you keep it grounded, or take it off? I usually keep it grounded until the light flashes.

 

 

That was the right plug. Now when I click on the picture, it show a VIN sticker!

 

You were too quick... I was editing the post trying to figure out inserting the pic rather than a link. HA!

 

Yes I kept it grounded. Tried different ground points and even different wires to ground it.

Three trips up and down the road too.... UGH!

Edited April 28, 2010 by sumguy67

[5523Pathfinder]

well, Im thinking either the fuse is already pulled/failed, the ABS control unit under the seat is done(let out the factory smoke), or possilby a wiring issue. Find the fuse and check it and go from there.

[adamzan]

I got code 9 on mine. Just did it.

[GrimGreg]

 

Now the fun begins..... I'll start with crawling under and checking visually.

Then pull the real wheels to look for more obvious stuff.

 

 

No need to pull the wheels, no ABS equip there, the sensor is on the pinion.

[sumguy67]

No need to pull the wheels, no ABS equip there, the sensor is on the pinion.

 

In digging through info and manuals I read something about the brakes causing a malfunction (I think)????

Besides, I want to check them anyway.

[Cuong Nguyen]

There's a Load sensing doohickey located on the inner middle of the passenger frame. you're suppose to bleed it first and continue on with the rest of the brakes. This thing is suppose of detect a load in the rear and "adjusts" braking when you're towing and it sags the rear. I can't tell the difference though.

[sumguy67]

I solved my ABS issue. Turned out it wasn't the ABS system.

 

I did notice my brakes were a little mushy but not unreasonable. And in regular driving I really didn't notice the lack of rear brake pressure.

There was a leak in the brake line over the axle. Very small and I didn't see any leak evidence because it had found it's self a sneaky path down a suspension bracket.

When I checked the brake reservoir (for the 5th time) I decided to try and fill it even tough it looked full. The full "look" was simply a stain on the plastic.

 

I feel stupid because that stain has caught me before on other vehicles.

 

Anyway..... replaced brake line, bled the rear system (including ABS unit), hammered the brakes on a gravel road a few times to activate the ABS.

The ABS light stayed on until I drove it for about another km. Which makes sense because it needs time to sense and reset.

 

Considering what came out when I bled the brakes I think I will be bleeding the entire brake system very soon. Besides, I like to bleed the brakes about a week after I change a line anyway.

 

Now to work on the broken bleeder nipple..... UGH!!!