EDTX

Can some with a 2001 or similar 4runner take a pic of the under hood diag port? I am being told there is a jumper that is preventing me form getting codes, but I must be blind because I do not see a jumper.

Thanks,

Ed

2ToyGuy

What you're looking for is labeled DLC1 in the diagram. I know it's not a picture, ut it's right out of the FSM, so it ought to help.

Are you looking to read the codes out with an OBD II code reader, or by the flashing CEL? If you're trying to see the codes using the flashing CEL, you need to not have the OBD II reader plugged into DLC3, and a jumper in DLC1, TE1-E1. If you want to use a code reader, yes, there can not be the jumper in DLC1.

Does this help any?
Pat☺

EDTX

Thanks for the reply Pat, My issue is I am using the DLC1 and performed the procedure that is supposed to result in the ABS dash lights blinking to give a code, but when I perform the procedure the ABS,Brake,VSC,TRAC off all remain solid,,, the Cruise and Airbag lights blink,,,, not an expected response. I was told there is a jumper in the DLC1 that might be preventing the ABS codes from being shown, but I see no jumper in my DLC1. I did use an OBD II and had a P0500 code -- VSS. But the truck shifts fine and I believe a symptom of bad VSS is tranny not shifting, I even disconnected the VSS and the truck stayed in 1st gear. I am going to try an get a voltage reading at the ECM from the VSS to be sure. Next I think I would like check each ABS wheel sensor, but need the wire diagram of the ABS module on the driver side under dash,( having trouble the diagram), since the wheel ABS sensors do not have a connector at the sensor but a long run in a bundle(crazy), back to the module. Otherwise the truck runs and brakes normally. I even changed the gas cap, based on a youtube suggestion...Running out of ideas here.

2ToyGuy

Well, According to the book, if you are getting a valid, accurate, vehicle speed when moving, the ABS wheel speed sensors are all working correctly. The VSC ECU, located above the interior fuse block, on the body, takes all 4 of the ABS wheel sensor inputs, combines and shapes the pulses into a single, 4 pulse, signal, which is then fed to the speedometer in the combination meter. The frequency of the pulses, IOW, how close the second SET is after the first SET, AND, how close the pulses in a set are together, is used to display speed on the speedometer. After that, it's fed to the main ECU as a 4 pulse signal. Again, the ECU uses frequency to determine vehicle speed for various purposes, like control of the A/T.

It would be best to use your OBD II reader, in freeze-frame mode, to determine what the pulses are doing. If you want to look at them with an o'scope, the book recommends looking at them at the ECU, see attached pictures.




Are those any help?
BTW: Apparently, you can try and read the pulses with a multimeter, in voltage mode. But a digital meter would be more difficult to use than an analog meter, OR an o'scope.
Pat

EDTX

First I'd like to say thanks for the informative responses I received from 2toyguy. Secondly I will give a brief OV and my solution for anyone interested.
Check My post below from 6/29 first. I performed all the testing to get codes as previously mentioned and never could get any response from the diagnostics systems of the 4runner. Which started to get me thinking it was a system issue not a specific component issue. I check voltage at SP1 of the ECU while turning each wheel, the odd thing was I would get varying voltage readings when no wheels were turning and it continued when I turned each of the wheels. I should mentioned that I also had a P0500 code pointing to the VSS, which is connected to the tranny on the drivers side, I did replace it first and nothing changed. So using the solution from a previous post I went ahead and obtained a used ABS module - cost me $220 on ebay. I disconnected the battery for 1 day to ensure all codes were erased and replaced the ABS module, very simple 2 bolts. The Brake/VSC/TRAC/ABS lights cleared and the P0500 code has not returned after 75miles of driving and the speedometer is now working, so I am hopefully closing the books on this one.
One note: When I performed the procedure to get the codes using a jumper at the DLC1, the only blinking lights I had were the Cruise Control and Airbag and they did NOT blink in any noticeable sequence. The Brake/VSC/TRAC/ABS all remained on steady.
So if the ABS module is bad I can see why I couldn't get any diagnostics out of it.
One last note, the 4Runner operated fine the entire time the lights were on, maybe the ABS was not functional, I don't know, but nothing prevented me from driving the vehicle and feeling safe,, except for no speedometer -- good excuse if pulled over????
Hope that helps.
Ed

rblderr19

i have a 98 4runner, and the tech found it hiding right up against the center radio console.