Code 12 - no rpm signal

[NewWestSupras]

Hi all, I keep getting a recurring code 12, "no ne of g signal to ECU within 2 seconds after engine has been cranked". Unfortunately, this is all Borg to me.
"Trouble areas: cps, cps circuit, starter signal circuit, ECU".
The car seems to run okay, but sometimes it takes up to 3 seconds for the starter to engage. I'm thinking starter wiring or starter itself... I don't want to go off half cocked and start pulling the starter if I could troubleshoot the problem better beforehand.
Mods are: rebuilt engine, 550's, lex, 3" exh. & dp, afpr, MKIV denso fp, Turbonetics 60-1, stock ems. I've inspected the cps wiring, and it "seems" ok...
Will this code affect performance? I have reset it, but it comes back. As I said, it sometimes doesn't want to start right away. Thanks for looking.

 

[RedGT]

The computer looks to see if there is a crank signal when you crank the engine, so if your starter is not engaging for 3 seconds this code will set. I had the same problem. Try replacing the starter.

 

[isnms]

^correct starter or circuit to starter

...sometimes it takes up to 3 seconds for the starter to engage...

12 |RPM Signal
Diagnosis |No "NE" or "G" signal to ECU within 2 seconds after engine has been cranked.

 

[NewWestSupras]

Ok, thanks. will do. Does this code hamper performance?

 

[supradjza80]

No "NE" or "G" signal to ECU within 2 seconds after engine has been cranked

doesn't this imply that the motor is cranking for 2 seconds with no signal? I had a no start issue with my starter and I never received a code 12 when the starter would just click. I doubt the starter is the cause of this code.

 

[isnms]

I doubt the starter is the cause of this code.

Yes it can be:
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=044

(11) STA Signal System: To confirm that the E/B is cranking. The voltage applied to the starter motor during cranking is detected and is input as a control signal to terminal STA the ECU.

 

[RedGT]

the computer thinks its cranking when you turn the key to crank, and you dont get a cmp signal it sets the code

 

[easternguy2005]

My experience today with this same code and fix. Car ran perfect previous day. Came out to start and it turned over but didn't try and fire. Thought I flooded it (although that never happened b4) so walked away for 1/2 hour. Tried again, smelled gas coming out of exhaust. Codes were checked and clear just 2 weeks ago, today pulled a 1-2 code. Jiggled wires to that CPS by the pwr steer reservoir. Tried again no go. Unplugged and inspected connector there - looked good. Try again no go. Half heartedly took the plastic cover off cps and saw some oil on the bottom, damn o ring.....maybe another day. Cleaned inside up with a soft rag. Turn her over and started right up. Ran for a few mins. Cleaned it out with a cotton swab and rag. Put back together. Starts up. Cleared code in meantime to keep an eye out for it showing up again.

Thought I would pass that on because it was a no start show stopper problem that was solved.

8 mm wrench or socket for cover