With 4L60 Automatic Transmission

Code 22 - Throttle Position Sensor (TPS) Circuit (Signal Voltage Low):

Wiring Diagram For Code 22 - Throttle Position Sensor (TPS) Circuit (Signal Voltage Low):

CODE 22 - THROTTLE POSITION SENSOR (TPS) CIRCUIT


CIRCUIT DESCRIPTION:

The Throttle Position Sensor (TPS) provides a voltage signal that changes relative to the throttle blade. Signal voltage will vary from about .5 at idle to about 5 volts at wide open throttle.

The TPS signal is one of the most important inputs used by the ECM for fuel control and for most of the ECM control outputs.


TEST DESCRIPTION: Step numbers refer to step numbers on diagnostic chart.

1. Code 22 will set if:

^ Engine running
^ TPS signal voltage is less than about .2 volt for 3 seconds.

2. Simulates Code 21: (high voltage) If the ECM recognizes the high signal voltage the ECM and wiring are OK.

3. TPS adjustment: (2.8L) With throttle closed, the TPS voltage reading should be .48 volts +/- .06 volts.

4. This simulates a high signal voltage to check for an open in CKT 417.





DIAGNOSTIC AIDS:

A "Scan" tool reads throttle position in volts. Should read about .73 volts (2.5L), .48 volts (2.8L), .60 volts (4.3L & V8) +/- .08 volts with throttle closed and ignition on or at idle. Voltage should increase at a steady rate as throttle is moved toward WOT.

An open or short to ground in CKTs 416 or 417 will result in a Code 22.

DIAGNOSIS BY SYMPTOM - NO TROUBLE CODES STORED.

"Scan" TPS while depressing accelerator pedal with engine stopped and ignition "ON". Display should vary from below 2.5 volts (2500 mv) when throttle was closed, to over 4.5 volts (4500 mv) when throttle is held at wide open throttle position.