check engine light is on and my idler goes up when i press the brakes

[jose vargas]

hey i was wondering if any one had the same problem my check engine light goes on and the trouble code say its a trany sensor but since its a manuel mazda says it doesnt have one they told me its the egr valve sensor that will fix that and my idleing problem that is when i press my brakes my engine idels high and goes down when i press the clutch any one help

 

[xelderx]

There is a sensor on the transmission that will cause this to happen if it is bad or not plugged in. I ran into the same problem on a MSP when I dod a motor swap. I forgot to plug that sensor back into the wiring harness and go the exact same symptoms you described. I'm pretty sure the sensor in question is on the back of the tranny directly under the brake master cylinder, but I'll have to take a closer look tomorrow when I'm off work.

 

[Kansei]

Interesting.. I'm having the opposite happen. If I plop it in neutral and take my foot off the clutch pedal, the idles droop way low but as soon as the car comes to a complete stop (using the brakes), after a second or two the idle picks right back up.

I just changed my wires and plugs today and on the one trip I made it didn't do it, but it only seems to do it when the engine is cold in the mornings.

 

[Luni]

Your brake master cylinder is your clutch master cylinder. Its called a tandem cylinder. If you use the clutch or the brakes the brake booster has to work to assist it.

If youre pulling a CEL then have autozone (or if you know someone with a code reader) scan it, and post your code. These guys can tell you what the code is.

There are actually 2 sensor plus to the tranny. One plus into the harness endds that go to the coolant neck, and the other plugs in underneath the brake master cylinder, its a squarish plug.

Make sure your plugs are all plugged in.

Make sure your vacuum lines are all correctly plugged in. Especially the big fat main one from the intake mani.

 

[njaremka]

Your brake master cylinder is your clutch master cylinder. Its called a tandem cylinder. If you use the clutch or the brakes the brake booster has to work to assist it.

uh, not quite. they share the same fluid reservoir, but not cylinders. if they shared cylinders, each time you hit the clutch it would also activate your brakes, and vice-versa.

jose vargas -
you need to post the actual code for us to properly help you out.

 

[Luni]

Oh yeah, never though of that. LOL sorry.

But for real, need the code.

 

[jose vargas]

ok thanks i,ll check tomorrow that sensor if anyone post a pic of wat im looking for please thanks guys for ur help

 

[njaremka]

whats the code?

 

[jose vargas]

i got 2 codes one is P0705 / P0507 HELP