A Different HID Issue

Greeting folks, I am hoping someone out there has a suggestion as to where I can continue my search for this issue.

I have a 2006 with the Dreaded HID system, I have been through the issue we are all familiar with back at 65K miles with the dealer, had my bulbs replaced and the computer. I am now at 170K on my Prius and had the bulbs fail again, not wanting to pay for the Phillips bulbs I opted for a pair of MAXLUX 6000K bulbs.

All was fine for the first 2 months then I started having intermittent failure of Both lights at the same time, High and Low beam. Light indicator on Dash is on, High Beam light comes on so switches are good. Checked Fuses under the hood for Lights, also Good. Swapped out the relay for the lights and thought I fixed it. Wrong, still had issues. Now the light don't come on at all and I'm not sure where to look next.

Any Suggestions? Hopefully I did not kill my ECU with these bulbs.

 

That's for sure 1 of my possible ways to go, but I'm reserving that one as an "if all else fails" type of solution because I'm not dealing with Toyota on this. I was wondering if anyone had experience with swapping out bulbs like I did. Wondering if the stock HID system just doesn't like the new bulbs.

 

It would be really disappointing if it is the bulbs, because there only 2 months old, but I have never used these before so they may be garbage bulbs.

 

Have ordered 2 OEM Phillips bulbs from Amazon for for 45 a pop with free shipping. Hopefully this is all it is.

 

I don't think the bulb's alone are going to solve this, did some testing with a multi-meter this evening. No power to either Headlight fuse, however there is power at the Relay. Found another thread that suggested the DIM relay may be the issue, need to bench test the relay at a buddies tomorrow....if that isn't bad I may be looking at the ECU, if it is them guess I'll just replace with an aftermarket kit.

 

Will do....after digging around the site I found the links to the Toyota tech service manual, so that will go a long way for my troubleshooting efforts...stay tuned.

 

I have done some testing in the Relay bank and made a discovery, if I jump 12v from the jump start terminal over to the #5 terminal of the H-LP relay socket, VOILA.... my light turn on. So at least now I know it's not the bulbs or the ballasts. I also know this relay to be 100% good, I have even put a new on in just to be sure. So it would seem I'm not getting a signal from the ECU to energize the relay, just great.

So now it's off to the ECU terminal block to check the B7 connector, hopefully it's just loose or something.

More later....

 

Ok, so after tearing into the drivers side ECU location I made my way to ECU and located the B7 connector. Per the Toyota service guide I disconnected B7 and grounded Terminal 20...nothing....also as per the Toyota guide I tested B7-20 for voltage, should be between 10-14 VDC....my reading 0.45....at this point the guide says to replace the harness and the connector. Yea i don't think so.

Being as I can make the lights come on by manually triggering the relay I think my solution to this going forward is to simply install a switch in the dash in one of the blanks and simply use this to switch the lights on.

If anyone has another suggestion, I am open to ideas.

 

The only viable solution I can see at the moment is to try to jumper the bad lead with a new wire, not an easy task considering where the harness is located, but this is my next course of action I believe.

 

OK this is now confirmed, Splicing a lead off B7-20 from the ECU to the Coil terminal on HRLY (cold side not the 12V hot side) had put the headlights back into proper operation.

OK so now that having been said I know the "Proper" way to fix this would be to replace the harness. I am very concerned that this lead went bad in the first place but I'm out of Warranty and out of luck. I don't know what the cost to replace it would be but I would venture a guess at around 900 Bucks at least. So for now I think I'm just going to carefully route the lead up to the Engine Room and call it a day.