Code 51

[edi]

whats a comon fix for a Code 51? the TSRM says this:

Switch Signal

-Diagnosis
No "IDL" signal, "NSW" signal or "A/C" signal to ECU, during diagnosis check.

-Trouble Area
A/C switch circuit
A/C switch
A/C amplifier
Throttle position sensor circuit
Throttle position sensor
ECU

would this be why i have a 1100-1200rpm idle? which of the discribed touble areas above would you tackle first?

 

[Boss302]

have you adjusted the idle control screw or seen if you throttle plate is possibly not closing all the way. just my 2cents.:nono:

 

[edi]

i just finished adjusting my idle to 10deg. the previouse owner had it all jacked up. so now my idle is steady at 1000rpm. if i changed out or adjusted the TPS would my idle drop to normal rpm?

 

[edi]

i'm sorry, i ment adjusted my timing.

 

[Joel W.]

Yes, it should drop down once the TPS is adjusted (code 51 not present) and the timing is properly set with the jumper installed as long as everything else is working properly.

 

[edi]

i just took my car for a test drive after adjusting the timing and what a difference that was! it pulls so much stronger. i'm wondering how much better it will feel once i get this code 51 fixed and cleared.

 

[Joel W.]

How did you adjust the idle? If your still referring to adjusting your timing, then you probably just gave the ecu more advance to play with... Just a guess here. Reread the above...

 

[edi]

sh!t... i keep mixing it up. i ment timing. i never adjusted the idle, only timing. sorry again.

 

[Joel W.]

LOL.. Ok now fix the code 51 and reset the timing again..let us know whats up...

 

[djordan97]

ok now when the tsrm says till the ohm meter deflects how do you figure that out when you don't have a needle style ohm meeter.

 

[edi]

thanks. i'll try this. i hope i dont jack things up. i dont like messing with electronics.

 

[mhopemk3]

OK.. When checking the codes make sure you are only showing 51.. It is much easier if you have someone to help you. While flashing a 51 move the TPS a little until your check engine light is on a fast blink. Keep adjusting until you just the slightest movement of the tps will throw a 51. When you have it at that point tighten it down and while your check engine is steady flashing(clear) press the gas pedal just a bit and it should throw a 51. When you let off the gas it should go back to clear.. You have to wait a second between the clear flash and 51 code..

Hope this helps..

 

[edi]

this way seems much easier than doing it the the way that the TSRM says. but, if the the code doesnt go away with either the two way to adjust the TPS, that would mean i have a bad TPS?

 

[mhopemk3]

More than likely.. I can't say for sure.. There are more knowledgeable people here than me... I just have experience with the Code 51.. What a pain.. It seems easier to me than doing the TSRM method.. I don't remember who posted about the throttle but you do need to make sure the throttle is completely closed if the idle doesnt come down. I know my idle was still a little high because the bottom screw was not in the tps only the top one. When I put one in the bottom I idle around 700..

 

[edi]

question, how do i get to the lower of the two screws that loosen the TPS so that i can adjust it?

 

[Joel W.]

If you have a 90 degree phillips screwdriver or pull the ISC valve off real quick so you can access the screw...

 

[jetjock]

Having fun Joel?

That "deflects" thing with the meter....it's amazing how often that gets asked

 

[Joel W.]

Yes, LOL, I do not know how to explain it either when it comes to a digi meter?? Mine says (0L. Ohms) then deflects to (00.0 ohms)??

I like the beep instead..:biglaugh:

 

[jetjock]

That it needs to be explained at all is what's amazing.

Good posts btw. Shows a solid grasp of the issues associated with 51. The key is just what the book says: No IDL signal, NSW signal or A/C signal to ECU, during *diagnosis check*.

 

[Joel W.]

Thank you!! I figure with enough explainations I will have one thread refined enough to "sticky" someday LOL...

Yeah that makes sense now... LOL