Throttle Valve Switch Test - Code 23
- Check throttle valve switch for continuity between terminals 18 and 25. See Fig 1 . If there is continuity, go to next step. If there is no continuity, adjust switch so that switch turns on at idle A 250 RPM. If not adjustable, replace throttle valve switch. If adjusted, go to next step.
- Check for insulation between terminals 18, 25, and ground. If no insulation, replace throttle valve switch. If there is insulation, perform ECCS self-diagnosis, and if okay, end test.
- On Maxima and 300ZX models, confirm idle switch operation. Turn ignition switch to "ON", and check voltage between 20-pin connector terminal No. 18 and 16-pin connector terminal No. 25. Battery voltage should be present. Voltage will change to zero volts when engine speed is reducing from 900 RPM. If incorrect, adjust idle switch so that the switch turns on at engine idle A 250 RPM.
- Disconnect ECU 20-pin and 16-pin connectors. Check for continuity between terminals No. 18 and 25. See Figure and Figure . With the accelerator pedal free, resistance should be zero ohms. With the accelerator pedal depressed, resistance should be infinite. If okay, replace the ECU. If not okay, go to next step.
- Check throttle valve switch. Disconnect throttle valve switch harness connector. Check the throttle valve switch for continuity between terminals No. 25 and 18. See Figure
. Continuity should exist with the throttle valve at idle, and should not exist when valve is slightly open. If not, replace throttle valve switch.IDLE SPEED SPECIFICATIONS
Application RPM Maxima & 300ZX 650-750 - Check harness for insulation. Resistance should be infinite between throttle valve switch harness connector terminals No. 18 and 25, between 18 and ground, and between 25 and ground. Connect harness terminals No. 18 and 25 with a lead wire and check for continuity between 20-pin connector terminal No. 18, and 16-pin connector terminal No. 25. If no good, repair or replace harness. If okay, replace ECU.