Brights don't work, Flashers do! HELP.

Hi, I have a 2005 DCSB Taco 4x4. While trying to figure out which wire does what in the fuse box (whhith a jumper wire and a multimeter) to tie in a set of hella ralleye 4000's , my brights stopped working. Though the flashers do work, so I know the Bulbs are fine, ALL fuses are good, and I even bought another stalk on eBay and plugged it in and it didn't fix the problem any ideas? no aftermarket lights wired to the headlights as of right now. the relays all seem to click. no indicator on dash when stalk is pushed forward, but when pulled back to flash it appears.

 

I am assuming that what you mean by flashers is that the headlights come on high when you pull the stalk back.

I would start with the DIM Relay and check voltage on pin 5 with the lights on and selected to high beams. Then select low beams and have someone flash the highs while checking voltage at pin 5.

I seem to remember another poster that had a similar issue and it was the Body ECU. I'll see if I can locate that thread.

Here it is a bit different but may help guide your troubleshooting without me retyping everything.

https://www.tacomaworld.com/threads/no-headlights.665247/

This may assist:

 

The only difference I see between Hiagh Beams and Flash is,

Flash send a ground signal to the HF and HU pins on the Body ECU.

The High Beams only send Ground to the HU pin on the Body ECU.

If you have power to pin 5 on Flash, but not on High.
The the only thing between the 2 is the Body ECU.

What do you think Jimmy?
I’m really hoping there is never power to pin 5.

 

This guy had the same problem.
Apparently the connector he took apart didn’t get put back together good.
Maybe make sure the harness is connect well.

https://www.tacomaworld.com/threads/flash-switch-works-but-high-beam-switch-does-not.450520/

 

That does appear to be the only difference HU and HF.

About the power to pin # 5 well he said the flash works, high beams do not...

He will need some voltage measurements while someone operates the switch to see what is really what. Seems kind cut and dry Switch Stalk, Wiring to the Body ECU or the Body ECU itself.

 

I suspect the body ECU myself, but am wondering how to go about finding one? or testing it to verify that it is really the problem?

 

Also, do I need to program new keys if i replace it?

 

I suppose you could check for continuity on pin 11 of C11 to GROUND.
Put the headlights on High, if there is continuity, move to connector 1l pin 9.
I’d start here, since you have tried 2 head light switches.
If it Is good there, it’s likely the body ECM.







Let’s wait and see if @Jimmyh agrees.

 

Thanks! that makes a LOT more sense. will try tomorrow. where exactly is C11 and 1? on the stalk or Body ECM?

 

That is exactly what I would do to verify the ground side of the circuit.

C11 is the connector on the stalk.

1l is the connector to the Body ECU from the stalk Red wire with a Green Stripe.

 

If I replace the Body ECM, do i have to get new keys?

 

Ok, I tested C11 (on the stalk tho) for continuity, and got a circuit when the brights where on from C11, Pin 11 to Pin 20. Pin 20 I surmise is ground? does that mean its the Body ECU? or is there another relay somewhere I could have burned out?

 

On the stalk switch C11 Pin 11 ( is the High Beam wire to the Body ECU ) read to pin 12 ( Pin 12 is ground ) resistance. Should read as a short circuit when the switch is on and in High Beam Position.

Or you could just read a continuity check from Pin 11 to any ground on the body. If it reads near zero Ohms with the headlights on and high beam selected then the switch is good as far as the high beam signal goes.

If so that only leaves the wire between the stalk switch and the Body ECU ( Red Wire with a Green Stripe ) or the Body ECU itself.

Pin 20 (HEAD) is the Headlight Signal to the body ECU.
Pin 11 ( HU ) is the High Beam Signal to the body ECU.
Pin 17 ( HF ) is the Flash Signal to the body ECU.
Pin 15 is the Left Turn signal.
Pin 13 is the Right Turn signal.
Pin 12 is the Common Ground for all signals.

 

OK, everything seems to point to the body ECU, I located one, but before I order it i'm wondering if i'll need to program new keys which, if i do I will need to a key programmer too.

 

You shouldn't have to reprogram anything. The keys are read by the Key amplifier and feeds that data to the Transponder Key ECU which is separate from the Body ECU.

 

Got them working, it was the Body ECU! bought a replacement on eBay.

 

Good job!

Thanks for the update. I was pretty damn sure it was after all the checks.

 

Thanks for all the help, never could have figured it out without you guys!