DTC 22

Code 22 Chart:

Code 22 Wiring Diagram:

CIRCUIT DESCRIPTION:


The Throttle Position Sensor (TPS) provides a voltage signal that changes relative to the throttle opening. Signal voltage will vary from about 0.4 volt at idle to about 5 volts at wide open throttle (WOT).

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.

Code 22 will set if:

^ The ignition key is "ON".

^ TPS signal voltage is less than 0.24 volts for 4 seconds.


TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart.

1. With the throttle closed and ignition on at idle, the voltage at terminal "YF13" should be 0.33 to 0.46 volts.

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

3. With the throttle closed and ignition on at idle, the voltage at terminal "YF13" should be 0.33 to 0.46 volts. If not check adjustment. If TPS cannot be adjusted replace.

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


DIAGNOSTIC AIDS:

^ A Scan tool reads throttle position in volts. 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 in circuits 416 or 417 will result in a Code 22.

Check For:

^ Poor Connection or Damaged Harness Inspect ECM harness connectors for backed out terminal "YF13" or "BA4", improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection, and damaged harness.

^ Intermittent Test. If connections and harness check OK , monitor TPS voltage while moving related connectors and wiring harness. If the failure is induced, the display will change. This may help to isolate the location of the malfunction

^ TPS Scaling. Observe TPS voltage display while depressing accelerator pedal with engine stopped and ignition "ON." Display should vary from closed throttle TPS voltage when throttle was closed, to over 4.2 volts (4500 mV) when throttle is held at wide open throttle position.