DTC 22

Code 22 - Throttle Position Sensor (TPS):

Wiring Diagram for Throttle Position Sensor (TPS):

CODE 22 - THROTTLE POSITION SENSOR (TPS) CIRCUIT (SIGNAL VOLTAGE LOW)

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 (WOT).

The TPS signal is one of the most important inputs used by the Electronic Control Module (ECM) for fuel control and for most of the ECM control outputs.


Test Description: Numbers below refer to circled numbers on the 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: With throttle closed, the TPS voltage reading should be .55 volt +/- .075 volt.

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

5. CKT 416 is a common sensor ground buffered reference signal. If this circuit is shorted to ground, Code 22 will set. Be sure TPS is connected and clear codes before testing.


Diagnostic Aids:


A "Scan" tool reads throttle position in volts. Should read .55 volt +/-.075 volt with throttle closed and ignition "ON" or at idle. Voltage should increase at a steady rate as throttle is moved toward WOT.

Also some "Scan" tools will read throttle angle 0% = closed throttle 100% = WOT An open or short to ground in CKTs 416 or 417 will result in a Code 22.

Refer to "Intermittents" in Diagnosis By Symptoms - No Trouble Codes Stored.