Throttle Full Open Switch: Testing and Inspection

Idle/Throttle Switch Schematic:

A faulty idle/throttle switch may set either of two codes in the on-board diagnostic system. Code 42 will set if the idle switch is defective and code 43 will set if the power switch is defective. Refer to the schematic diagram and test the sensor with the diagnostic chart.

Wire color code identification:

L: Blue
B: Black
Y: Yellow
G: Green
R: Red
W: White
Br: Brown
Lg: Light green
Gr: Gray

Idle/Throttle Switch Diagnostic Chart:

IDLE/THROTTLE SWITCH DIAGNOSTIC CHART

ECU Connectors:

CHECK VOLTAGE AND RESISTANCE

1. With ignition "ON" and engine not running, measure voltage across ECU connector terminals as follows:

Connector & terminal: Voltage:
(F120)6-(F121)1 Below 1V (fully closed throttle)
(F120)6-(F121)2 Above 8V (fully open throttle)

2. With ignition "OFF," disconnect ECU connector and measure resistance between ECU connector and switch connector as follows:

Connector & terminal: Resistance:
(F120)6-(F108)3 Below 1 Ohm
(F119)1-(F108)2 Below 1 Ohm
(F120)10-(F108)2 Below 1 Ohm
(F120)6-Ground Infinite
(F119)1-Ground Below 10 Ohms
(F120)10-Ground Below 10 Ohms

Idle/Throttle Switch Testing:

CHECK IDLE/THROTTLE SWITCH

1. With ignition "OFF," disconnect switch connector.
2. Measure resistance between switch connector terminals as follows:

Connector & terminal: Resistance:
(F108)3-(F108)2 Below 1 Ohm (fully closed throttle)
(F108)3-(F108)2 Infinite (fully open throttle)