red ! triangle and yellow headlight symbol

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JeffD

 

Headlight leveling system ... I assume have HID headlights.

 

That depends. You could replace it yourself and buy a new sensor for about $300 or you could repair the one you have now.

You won't know if the sensor you have now is repairable until you disassemble it. Mine was repairable and it works (for now).

 

Others from northern states, with salt on roads, have reported this problem. The corrosion can hopefully be cleaned up. I seem to recall another thread here somewhere with pictures of the process.

 

This is the exact problem I have - Red triangle and yellow headlight symbol. How can I confirm it's the leveling system?

 

I would think this should give a DTC, read by a scanner.

 

I had these codes:

P0003
P0004
C2D86
B0667
C2086
B0665

Then I cleared them and the red triangle and head light symbol were still there. I checked the codes again and there were none.

 

If I recall correctly, the headlight sensor does not post a trouble code.

 

That warning illuminates when there is a fault with the headlamp leveling sensor that is attached to the rear axle beam. Normal procedure is to replace the unit, however I have been able to restore them by soaking the unit where the pivot arm comes out in pb blaster. It can take several days of driving and soaking to get it to fully function again. This doesn't always work but is worth a shot before sinking money on new parts.

P.s. this is actually josh2008 posting, just didn't feel like logging my wife's account out

 

I just got it again. I was able to fix it the last time by taking the unit apart and cleaning the horribly corroded insides. One of the 3 springs looked brand new, the other two were so corroded they were barely recognizable as springs. I made new ones from the core of a coax cable. One joint of the articulating arm was frozen solid, I could barely move it at all with a vice and a pair of vice grips. A kindly PriusChat member sent me one he had and I put it in place of my bad one.

This time was worse, all springs really corroded and if I didn't know what it was supposed to look like I would have never guessed there was anything in the area of the springs but hard dark brown gunk. Not repairable this time. One of the spade connectors is broken, one of the contacts on the potentiometer is broken and a lot of the black contact areas are no longer there. Again it is a wonder it didn't throw the error a LONG time ago. One joint of the articulating arm still very loose (as it should be) one a bit tight but some PB Blaster and it loosened up. Put some sewing machine oil on it and it is all good. But of course I don't need it. I'd be happy to send it to anyone who has a good potentiometer but a frozen arm. Toyota, it all its money grubbing glory, sells the bracket, arm and potentiometer as a single unit. You can not buy the parts separately which is a HUGE rip off.

I would suggest that ANY ONE with a 2004-5 Prius with HID that has not had to replace this height sensor yet - GET UNDER YOUR CAR. Fixing either of these before they go bad will save a lot of money. The unit is held on by 2 10mm nuts on the axle and 2 10mm bolts on the frame. I'd start by PB Blasting the nuts on the axle and removing them. Of course, if they aren't at all rusty, you might not have a problem in the potentiometer but check the arm anyway. Pull the mounting bracket off the axle and make sure the arm flops around like a rag doll. Then take the 4 screws out of the plastic part on the big bracket on the frame and see if you have corrosion or springs. If there is nothing wrong, the springs might fall or pop out so watch for them. You can take the whole unit off the car so you aren't working on your back but I found the 3 wire electrical connector hard to get off the potentiometer and the spade connectors are pretty small and thin. If the springs are at all corroded, you probably want it out of the car to clean it up.

I have ordered a new one from Camelback Toyota. They had the best price ($268) and offered no fee Fed Ex ground shipping. If I recall, the dealer I stopped at in MA the last time wanted $350 for the part. No doubt they want to charge an hour of labor for something that should take them maybe 10 minutes if they know what they are doing.

But my problem is: The car is going in for 120K service on Monday, the part won't be here by then. I'm sure they won't do the state inspection with the Triangle and Problem icons lit. Can I jump the red wire to the white wire without frying anything to fool the car into thinking all is OK until the part comes? I don't need to drive at night before I can put the part in and I'll pull the jump wire as soon as I get the car back from the dealer. Otherwise, I will have take it back another time for inspection and that would be a pain. OR ... steal the part out of my wife's 2006 Prius for a few days. I'd put the new one in her car, it only has 60K miles so it might as well have a newer part. I'll just tell her that her car felt bad for my car and threw the error in a show of empathy.

 

It would be best to install the part from your wife's Prius into your car; then install the new part on her car after it arrives.

I'm not sure what would happen if you start connecting wires together without the sensor. The headlight ECU may be smart enough to produce a warning light if it doesn't see the expected resistance range.

 

Thanks Patrick. Unfortunately it is now too late for me to steal my wife's sensor. I didn't have time to get back to the forum until now. Guess I'll have to go back for the inspection at a later date. I was a bit worried about frying something. Better safe (and out a little time) than sorry ( and out a lot of money).

 

If I were faced with this situation, I would remove the bad sensor unit and tape off the wires. Then I'd tap into the wires at the Headlight Leveler ECU, under the dash at the far right side (passenger side). Take a 10K-50K pot (value not critical), outer connections to the purple wire (pin 2) and yellow wire (pin 20), wiper to the blue wire ( pin 5). Run the pot out to somewhere convenient, and manually dial the headlights to the right position for the load. The Blue wire needs to be somewhere between .5V and 4.5V, according to the service info. The ECU might quibble if outside that range.

I am sure this is too Rube Goldberg for many here. Just my 2 cents worth.

 

Too much work! Besides, I'd have to figure out what a 10K-50K pot is first, then go figure out where to get one!

In the end, they ignored the warning on the dash and MFD and passed the car I told the service guy I had it on order. Good enough for him I guess. I did have to drive late last night and didn't notice anything odd. Lights seemed to be OK, definitely not shining too high and they weren't real short either.

So, after I change the oil this weekend (they do NOT get to screw that up again, the first few times was enough) I'll be all set for the drive to Cleveland (actually Strongsville) next week with new plugs, engine air filter, cabin filter (I do that, they wash well and I don't charge 15 minutes of labor for a 2 minute job) , lubed brakes, serpentine belt (apparently the original was cracking. Kinda gotta expect a belt to wear in 124K miles) and alignment on the right front. I was a little concerned about the plugs when he called to tell me about the belt and ran some prices on the other stuff. They were cheaper than he was expecting so he said maybe the older Prius uses platinum. But some searching shows that the 90080-91184 they put in is the correct Iridium plug for a Gen II Prius.

Thus, yet again the little Prius comes through. VERY minimal maintenance costs, 124K miles and ZERO problems with anything related to the hybrid system. Everything has been normal car wear , less than any car I've owned before and I've never kept a car to 100K miles until this car.

 

All set. Got the part, installed the part, no more error icons.

Drove to Strongsville, OH Wed, came back today. ~ 600 miles each way. Averaged just over 50 MPG. 65 MPH on the Interstate just doesn't give the good mileage and lots of hills on NY 8 between Utica and I/87. Nice drive on NY 8 though and some great 19th century house architecture in the old towns.

Car ran great, over 126K miles now.

 

nh7o, I did this last night and it worked great. For anyone else looking for a solution, here's some notes...
I used 3.3K ohm resistor connected to 10k ohm resistor. That left me with top (10k lead), bottom (3.3k lead), and middle legs. I put the top on the 5V line, bottom on the ground line, and middle in the middle line. I just jammed the leads into the connector that goes to the level sensor in the rear of the car next to the wheel. I covered it all in electrical tape and then used zip-ties over that to make sure the tape stays on. Yes, it's a bit "Rube Goldberg", but worst case is I get the warning light back in a few days. However, I'm hopeful this will be a final fix and it only took 15 minutes. I loose the auto-leveling feature, but I honestly can't think of a situation that I'd need that other than tonight when I'm going to drive home with 30 landscaping bricks in the back of my trunk. But, that's a very rare event.

 

I have a similar problem and would like to give this solution a try. The actual leveling unit near the left rear axel has been removed. Now I want to install a potentiometer on H12, as has been discussed. My problem is that I don't know how to obtain access to that connector. Do I need to start taking things apart on the car interior. I did remove one panel just under the glove box and found a single connector, but I don't think that is H12 (it has the wrong color wires going into pins 2,5,20. Any help would be appreciated.

 

I had the same exact issue on my 2005. Water gets into the leveling sensor (potentiometer) and corrodes everything inside. Its takes longer than the standard warranty to fail and the dealer gets $500+ for it. You can't pass inspection with this code.

I believe the seal has been improved, but the linkage arm still freezes up. My second sensor is frozen and the linkage broke. Fortunately its in a good position so I'm leaving it alone.

The word "sensor" is from the Latin meaning $500.