Replaced height sensor, still not working...

[patmeclark]

quick history: just bought my truck a couple weeks ago and AHC was not working. PO said it had to do with him doing the DVD bypass, but seems like that was bunk. Took it to the dealer and for $176 they did a zero point calibration, filled up my tank and let me know my FL height sensor was seized. Funny thing is that when I got the truck back from the dealer, I got it to go into HI mode, kinda. It took a little coaxing (going from P to N to D and or driving slow) but it worked!

So I replaced the sensor with a Dorman and AHC is still not working (and now I can't even coax it into HI like before). I did my best to make sure the connector was seated well, it was clean and "clicked" securely. I also made sure the arm was seated on the sensor properly. I don't have techstream so I jumped TC to E1 and got C1712 (1 flash then 2 flashes) and C1776 (seven flashes then 6 flashes). Pumped the brakes 9 times and there was some humming and buzzing, but the 1 flash 2 flashes sequence keeps repeating. Turned off car and took out key to try again, same result.

I also pulled the 50 and 30amp fuse prior to the diagnostic, for about 5 minutes, which of course didn't work.

So where do I go next? Can I check voltage on the harness side with the car on to see if wiring is good? Anything else?

 

[patmeclark]

Bump

 

[DirtDawg]

Looks like your getting a speed sensor code and a FL height sensor code. I would use FSM instructions and test all height sensors for the correct voltage range. Same with speed sensors. Techstream would really help.

 

[patmeclark]

Got it working! turns out one of the wires to the sensor terminal was severed. It was super close to the terminal itself so I couldn't splice it. Luckily the local Toyota dealer had a single repair wire for $10 which made it a relief of a repair! My suspicion is that the wire was nearly severed before I changed out the sensor (which is why it worked sometimes and not others), and then fully severed upon re-installation of the terminal to the new sensor. Anyway, it all works now, thanks for the help!