Throttle Full Open Switch: Testing and Inspection

CIS Turbo ECU Harness Connector (Pin # Locations):

1. With ignition switch turned "on", disconnect throttle switch connector and check voltage between harness side connector terminal #2 and ground. Should be battery voltage. If not check for open or grounded circuit between harness connector terminal #2 and terminal "B15" of fuse relay panel.

2. Connect ohmmeter between terminals #1 and #2 of switch side of connector.

3. Open throttle about half way and close slowly, while observing the resistance.
- Resistance should be infinite (idle switch open) while throttle is open and then go to zero (idle switch closed) when throttle stop is within approx. 0.7mm (0.028") of idle stop adjustment screw. Adjust position of idle switch if necessary, by loosening the the two fastening screws and rotating entire throttle switch assembly until idle switch has continuity at the prescribed position.

4. Connect ohmmeter between terminals #3 and #2 of switch side of connector.
- .Resistance should be infinite (open circuit).

5. Slowly open throttle all the way.
- .Resistance should remain infinite and then go to zero when throttle is within approx. 10~ of full throttle stop. The full throttle switch is not adjustable. It's position is predetermined when the idle switch is adjusted. If idle switch is OK, but full throttle switch is not or seems to require separate adjustment, replace entire throttle switch assembly.

If codes 2121 &/or 2123 were displayed and no problems have been found up to this point, check for:

a. Open or grounded circuit between throttle switch harness connector terminals #1 and #3, and ECU terminals #20 and #28 respectively.
b. open or grounded circuit between throttle switch harness connector terminal #1 and idle stabilizer unit terminal "8/LS".