My RR Diff and ABS Lights on Dash came on for no reason after driving my 04 Taco about 500 miles and towing 500# trailer. Next morning, RR Diff light was fluctuating from dim to bright, then, after about 5 minutes of warm up, RR Diff light went solid bright and ABS light came on again too. Does not seem to be related to vibration.

Thanks in advance for help! Here's the specs:

'04 Taco 3.4L SR5 TRD
56K miles
2.5" lift / 33" Tires
Recently added wiring harness for trailer lights
Was raining a bit during trip

 

if you have a factory locker then it sounds like its on wich shuts off the abs

 

Im sure you tried to switch off the locker, but, its normal for the ABS to turn off when the locker is engaged.

Honestly though that sounds like an eletrical problem if the locker is truely not engaged. You sure you cut the right wires

 

The light came on during driving in 2 wheel drive - all highway for the previous 500 miles or so... I stopped, put in 4Low, engaged OEM locker, RR Diff light blinked, turned RR Diff OFF, went back to 2Hi, ABS and RR Diff remained solid on.

Thanks for help...

 

No, locker was not engaged (at least I did not turn it on...). I purchases a trailer wiring harness esp. for 04 taco - had connectors that ran in-line with existing taillight connectors (no wires cut...) All the trailer lights work fine still...

Thanks for help...

 

If you engaged the locker (light blinking) but it did not lock and you shut it off, then maybe something i fishy with that. Lock it, get a solid light, then unlock it.

 

Actually this really sounds like the most probable problem.

 

You have bad speed sensor. Not sure about the Taco electricals, but my 99 Dodge had the differential speed sensor fail. It was $40 and 1/2 hour to replace.
The Dodge also had a sensor on the trans. The diagnostic machines could not find the problem, so it took me a while to find and fix it.

Also, don't cut the wires. The OBC needs sensor signals to keep things running right.

 

Thanks Godzilla! I 4 low-ed, locked er up, ran a 1/4 mile or so on a snowY dirt road, unlocked and both FF diff and ABS lights went out! Ran 30 miles or so in town in 2hi, 2 miles up dirt road in 4hi, no lights. Looks good so far

For the crowd out there: Does this appear to be a ECU issue with 500 miles of towing on 33" tires with no gear change, or, does this look like a sensor or other part going bad???

Thanks again Godzilla - Go YotaTech