Need some help with wiring Q45 TPS to 7MGTE harness

jetjock

jetjock

creepy-ass cracka
Jul 11, 2005
9,439
0
0
Redacted per Title 18 USC Section 798
Well, there ya go.

It's just a switch. When IDL and E2 are connected together IDL is pulled low to ground by E2. When they're not connected together IDL is pulled high by a pull up resistor in the ECU.

IDL can be "shorted" to ground (E2) without damage because another resistor in the ECU limits the current that would otherwise flow. Because of this the idle signal works "backwards" from a typical switch ie; the IDL line has no voltage on it when the switch is *closed*. The technique isn't used with electrical stuff because of the large amount of current it'd involve but it's quite common in electronics.
 
W

whitemike

Banned
Aug 30, 2009
1,164
0
0
Winter Park, Florida, United States
jetjock;1599810 said:
Well, there ya go.

It's just a switch. When IDL and E2 are connected together IDL is pulled low to ground by E2. When they're not connected together IDL is pulled high by a pull up resistor in the ECU.

IDL can be "shorted" to ground (E2) without damage because another resistor in the ECU limits the current that would otherwise flow. Because of this the idle signal works "backwards" from a typical switch ie; the IDL line has no voltage on it when the switch is *closed*. The technique isn't used with electrical stuff because of the large amount of current it'd involve but it's quite common in electronics.
Click to expand...

I'm curious as to why there's an IDL switch at all? Why can't the computer just say.. TPS is @ 0v .. so the TB must be closed? That seems more efficient in my opinion. However, I'm obviously not an expert on the subject.
 
W

whitemike

Banned
Aug 30, 2009
1,164
0
0
Winter Park, Florida, United States
jetjock;1599814 said:
I'm not in the mood to 'splain that right now but I will say if you'd just leave the damn car alone you wouldn't have these problems :)
Click to expand...

:cry:

That was mean jj. It's not my fault the tps was dead, and other than my backwards logic of the IDL circuit, I feel I did a decent job of troubleshooting..
 
W

whitemike

Banned
Aug 30, 2009
1,164
0
0
Winter Park, Florida, United States
jetjock;1599818 said:
You did great. Just yankin' your chain a bit is all. No malice intended...
Click to expand...

It's OK, I was fibbing on the crybaby emote (I wasn't really crying) albeit not far from it.. ;)

Thanks for the help! I guess I'm in the market for a TPS. I'm gonna grab a toyota one and the beech adapter I suppose. OEM or go home.
 
S

supraguy31

New Member
May 10, 2005
626
0
0
Pembroke, NC
WooHoo.....

Someone actually used my Wiring Diagram. These Q45 TPSs are a little stange at time. Very touchy when it comes to setting up the right voltages.
 
You must log in or register to reply here.
Top Bottom