[bigpaws]

I've seen this issue discussed a lot but I can't find an answer to my specific question which is this - As the check engine light isn't on, and there are no codes shown on my Ultragauge, I'm wondering if there are codes it can't read? From all I'm able to find out, it reads all the codes my FJ can throw...and has shown various ones over the years (2007 FJ).

It's my understanding that if it was an ABS wheel sensor, I'd see a code.
If it's the MAF, I'd see a code.

There are no codes shown, pending or otherwise.

Any thoughts on how to proceed besides the dealership?

Bill

 

[moodywizard]

Tech stream can read it I've heard.


Sent from my iPhone using Tapatalk

 

[bigpaws]

I'm wondering if it's possible there are codes in the ECU that the Ultragauge isn't showing me that another tool might, or, if being capable of reading CAN codes is all there is...

so, maybe it's the brake light switch (already ordered one - $35 is throwaway money considering what the dealer would charge just to look at it).

 

[chriskrossapplesauce]

Have you tried the easiest fix of all? Just unplug and plug back in the sensors on all four corners of the truck. One might not be making a good connection.

 

[bigpaws]

Hmmm. That's a very good point. I have not tried that. Quick question, as I seem to have great success breaking connectors when removing them, how do those come off? Need a flat head screwdriver, or something? Just pull?

Thanks!

 

[CurbCrawler]

Clear the codes and see if they return first, by disconnecting the battery for a minute and press the brake pedal with key on to bleed any stored energy. Reconnect and see what happens.

 

[bigpaws]

That's the thing - no codes are being shown (Ultragauge). It has shown various codes over the years, but, no codes today. Does that mean there are codes it doesn't show? It's a 2007 FJ

 

[chriskrossapplesauce]

Hmmm. That's a very good point. I have not tried that. Quick question, as I seem to have great success breaking connectors when removing them, how do those come off? Need a flat head screwdriver, or something? Just pull?

Thanks!

I think it's just a flat head screw driver. It's been a year since my cable broke so I could be wrong. Just don't man handle the thing! Sweet talk it and take it to dinner first :grin

 

[jimmiee]

I've seen this issue discussed a lot but I can't find an answer to my specific question which is this - As the check engine light isn't on, and there are no codes shown on my Ultragauge, I'm wondering if there are codes it can't read? From all I'm able to find out, it reads all the codes my FJ can throw...and has shown various ones over the years (2007 FJ).

It's my understanding that if it was an ABS wheel sensor, I'd see a code.
If it's the MAF, I'd see a code.

There are no codes shown, pending or otherwise.

Any thoughts on how to proceed besides the dealership?

Bill

First of all the only time the check engine light is required to come on is when an emissions related code sets. So if the code is not emissions related the CEL light may or may not come on.

The only tool that will able to see all the stored codes is the Toyota Tech-stream. Aftermarket scanners and code readers can usually see OBDII Generic codes but they have a hard time seeing the Toyota Manufacturer Specific Codes. Some scanners can see some manufacturer codes but not all of them. This includes the Scan-gauge and Ultra gauge. Professional Scanners like Snap On and the like are more apt to see the codes that cheap code readers can't see.

Disconnecting the battery will clear most but not all codes. An emissions related code will ultimately be cleared by the PCM itself. You can clear the code but it's still there. If you were to try to pass an emissions test after clearing a code you would be disappointed to learn the test would fail. The PCM needs one or two drive cycles before it clears the code.

One trick is to scan the PCM in OBDII Global mode and look at the rediness monitors. If there was a code and someone cleared it the readiness monitor would show the monitor is not ready. If you see this someone has cleared a code and the PCM is still waiting for the drive cycle to complete.

Finally it was mentioned earlier to disconnect the battery with the key on. NEVER do this! If you do you can fry your PCM especially if you hook the battery back up with the key on.

 

[bigpaws]

So, it may be a good idea to take my truck to my friend's shop (full-on garage) and try his Pro-level scanner. Hmmm. I believe his is Snap-On.

 

[bigpaws]

So...I had my ECM scanned by a professional scanner (Matco).

We drove a little while and confirmed that all 4 ABS sensors were reading properly.
It said I had a malfunctioning ABS module, and a foreign object on my RF ABS sensor.

Reset the warnings. Took a drive. Hit the brakes. Lights back on. So.... I removed the sensor and cleaned it off as there was crap on it. Then, replaced the brake switch. One thing I did notice was that to make the new switch seat properly, I had to insert it all the way and then pull up on the brake pedal to self-adjust it.

Problem solved. All lights off. ABS, etc all normal.

 

[bigpaws]

UPDATE...The next day:

Lights are back on. Sigh.

So, when he ran the *real* ODB scanner, it initially cited both the RF and LR ABS sensors. Being that there was in fact, crap on the RF as his scanner indicated, and I never even looked at the LR one, perhaps I'll give it one more try and clean both and see. Obviously, I did *something* that had the lights turn off for a little bit, so, that says I'm in the vicinity of the solution.

This is the first truly aggravating thing I've dealt with in 129,000 miles so, I'm hoping if I can get this behind me, maybe I'll have at least a little reprieve before the next one.

 

[bigpaws]

Update #2 : So, recalling that the Matco scanner indicated the LR ABS sensor as well, I pulled that and cleaned it. Lights are gone. It was coated with oil from my known-leaky axle seal. I'm sure the lights will come back because I can't get the seal fixed until after the holiday weekend, but, at least I know what's going on.

I thought anyone reading through this might like to know.

I love my FJ and I'm keeping it until it aslplodes. Then, I'll still keep it.

 

[Jai]

I have a similar issue going on currently, ABS VSC, traction control(and one other) lights are on. Toyota dealership in Houston confirmed that the front right sensor is bad. Upon investigation found out that there is some rust on the magnet part of the speed sensor. Once that was removed the lights went off. However came back after 2 miles of test drive. Before this happened, a month ago I got my bearings replaced at NTB and I believe they didn't seal it right which has caused debris to go in. No wonder the sensor only works for a bit before it reports back into the system.
NTB initially said that there is no way there can be rust in it and ABS sensor is not even related, but Toyota guys showed me how the magnet part of ABS sensor sits inside the hub close to bearing to sense speed etc. After taking it back again they agreed to fix it next week and re-assemble everything if needed to get rid of the light.

Lesson learnt: Not to authorize anyone to reset the lights as it erases the root cause reported (not sure if thats the right verbiage).

I will post an update once I have results from NTB's diagnosis.

 

[jimmiee]

I have a similar issue going on currently, ABS VSC, traction control(and one other) lights are on. Toyota dealership in Houston confirmed that the front right sensor is bad. Upon investigation found out that there is some rust on the magnet part of the speed sensor. Once that was removed the lights went off. However came back after 2 miles of test drive. Before this happened, a month ago I got my bearings replaced at NTB and I believe they didn't seal it right which has caused debris to go in. No wonder the sensor only works for a bit before it reports back into the system.
NTB initially said that there is no way there can be rust in it and ABS sensor is not even related, but Toyota guys showed me how the magnet part of ABS sensor sits inside the hub close to bearing to sense speed etc. After taking it back again they agreed to fix it next week and re-assemble everything if needed to get rid of the light.

Lesson learnt: Not to authorize anyone to reset the lights as it erases the root cause reported (not sure if thats the right verbiage).

I will post an update once I have results from NTB's diagnosis.

Good post and a good lesson. Erasing the code or disconnecting the battery cables also erases the Freeze Frame Data for the code. The FF Data is a report which helps the technician diagnose the problem.
:cheers: