pokgai
12-17-2002, 10:40 PM
So heres what i noticed. During the day, when your low beams are off, and you pull the lever towards yourself to flash the high beams, the low beams flash on as well. This is bad for those with HIDs.
So i went around trying to see if theres an easy fix to it. To that, the answer is perhaps. Me, I havent gone to college to get my bachelors in Electrical Engineering (i will this fall though), so this looks kinda weird to me. Also, I dont know where everything is located.
Thanks to "JustHitADeereWithHID" on the Philips Automotive forums, he provided a wiring schematic on a posible solutoin. here are the pics:
http://alexgts.home.attbi.com/GTS_page1.jpg
http://alexgts.home.attbi.com/GTS_page2.jpg
http://www.lighting.philips.com/forum/forum_6/messages/38169.shtml is the original question thread.
Here i what he said to do:
I figured out what you need to do, to fix that problem on your car. I'm looking at the diagram for your '01 Celica GTS. It has a system with an ECU 'Body' module, that has several inputs on it, and that module has a program in it (just like your powertrain ECU does), that sends out driver signals, but to the headlight relays, based on certain input signal status of those sensors. The module controls your DRL, lowbeam, highbeam, taillights, for dawn/dusk, etc. The input signals include: Automatic Light Control Sensor, Parking Brake Switch, and all of the headlight switch inputs (including: headlight-on, park/tail-on, high-on, or low-on, and flash-on). You need to unhook the FLASH-ON input from the switch, that goes to the Body ECU (which is a DIFFERENT ECU INPUT than the highbeam-on input), and you need to hook that instead, to trigger a separate added-in relay, that will apply power directly to the highbeam secondary circuit (which is isolated from the Body ECU's highbeam relay trigger [primary] circuit). In other words, the added-in relay you install will not affect anything else in that highbeam circuit, or any other lighting circuit, since the only other thing in that circuit is another relay controlling the positive side of the higbbeam circuit, and a DRL dimmer relay, which reduces the voltage from the negative (return) side of the highbeam circuit. But at any rate, adding in this manual flash-on relay on the positive side of the highbeam circuit wont cause bad things. It will make the flash-to-pass feature function just like you want it to
and also
Okay good. I noticed another thing in the circuit that needs to be modded as well.
There are 2 relays (of the 3 total) in the DRL circuit, that NEED to be jumped and bypassed, or this whole mod wont work. They are called DRL relays #3 and #4. Just unplug them and make a couple of 2 inch long jumpers that have the correct male spade connectors on each end, and connect a jumper between pins #3 and #5 on EACH relay socket. This is an important step. Both DRL sockets have the same terminal numbers, and they both need to be jumped (#3 to #5). This allows the highbeam circuit to always function in normal mode. The problem is when the 2 relays are not engaged, the 2 highbeam bulbs are wired in series for DRL mode (one relay switches the positive and the other switches the ground). Make sense? But those 2 relays get their power from the lowbeam-on circuit, so unless the lowbeams are on, the highbeams will only shine in DRL (reduced voltage) mode. Make sense? So just jump pins 3 and 5 on each relay socket for DRL relay #3 and #4 like I said, and then add in another separate relay like I said, hooked to the highbeam circuit (fused, or tapped-in before the OEM fuses), and disconnect the flash-on trigger wire (pin 12 of the Body ECU), and use that to be the switched ground (trigger) of the relay. I could send a revised wiring diagram of the complete mod, but probably not til tomorrow at best. Would you like me to e-mail one to you? Just let me know
i can kinda understand this, but id rather not try this. so if anybody knows whats goign on, please explain hehehe. Maybe ill try this later on.
So i went around trying to see if theres an easy fix to it. To that, the answer is perhaps. Me, I havent gone to college to get my bachelors in Electrical Engineering (i will this fall though), so this looks kinda weird to me. Also, I dont know where everything is located.
Thanks to "JustHitADeereWithHID" on the Philips Automotive forums, he provided a wiring schematic on a posible solutoin. here are the pics:
http://alexgts.home.attbi.com/GTS_page1.jpg
http://alexgts.home.attbi.com/GTS_page2.jpg
http://www.lighting.philips.com/forum/forum_6/messages/38169.shtml is the original question thread.
Here i what he said to do:
I figured out what you need to do, to fix that problem on your car. I'm looking at the diagram for your '01 Celica GTS. It has a system with an ECU 'Body' module, that has several inputs on it, and that module has a program in it (just like your powertrain ECU does), that sends out driver signals, but to the headlight relays, based on certain input signal status of those sensors. The module controls your DRL, lowbeam, highbeam, taillights, for dawn/dusk, etc. The input signals include: Automatic Light Control Sensor, Parking Brake Switch, and all of the headlight switch inputs (including: headlight-on, park/tail-on, high-on, or low-on, and flash-on). You need to unhook the FLASH-ON input from the switch, that goes to the Body ECU (which is a DIFFERENT ECU INPUT than the highbeam-on input), and you need to hook that instead, to trigger a separate added-in relay, that will apply power directly to the highbeam secondary circuit (which is isolated from the Body ECU's highbeam relay trigger [primary] circuit). In other words, the added-in relay you install will not affect anything else in that highbeam circuit, or any other lighting circuit, since the only other thing in that circuit is another relay controlling the positive side of the higbbeam circuit, and a DRL dimmer relay, which reduces the voltage from the negative (return) side of the highbeam circuit. But at any rate, adding in this manual flash-on relay on the positive side of the highbeam circuit wont cause bad things. It will make the flash-to-pass feature function just like you want it to
and also
Okay good. I noticed another thing in the circuit that needs to be modded as well.
There are 2 relays (of the 3 total) in the DRL circuit, that NEED to be jumped and bypassed, or this whole mod wont work. They are called DRL relays #3 and #4. Just unplug them and make a couple of 2 inch long jumpers that have the correct male spade connectors on each end, and connect a jumper between pins #3 and #5 on EACH relay socket. This is an important step. Both DRL sockets have the same terminal numbers, and they both need to be jumped (#3 to #5). This allows the highbeam circuit to always function in normal mode. The problem is when the 2 relays are not engaged, the 2 highbeam bulbs are wired in series for DRL mode (one relay switches the positive and the other switches the ground). Make sense? But those 2 relays get their power from the lowbeam-on circuit, so unless the lowbeams are on, the highbeams will only shine in DRL (reduced voltage) mode. Make sense? So just jump pins 3 and 5 on each relay socket for DRL relay #3 and #4 like I said, and then add in another separate relay like I said, hooked to the highbeam circuit (fused, or tapped-in before the OEM fuses), and disconnect the flash-on trigger wire (pin 12 of the Body ECU), and use that to be the switched ground (trigger) of the relay. I could send a revised wiring diagram of the complete mod, but probably not til tomorrow at best. Would you like me to e-mail one to you? Just let me know
i can kinda understand this, but id rather not try this. so if anybody knows whats goign on, please explain hehehe. Maybe ill try this later on.