DTC 22

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

Throttle Position Sensor Wiring Circuit:

Circuit Description:

The Throttle Position (TP) sensor provides a voltage signal that changes relative to throttle blade angle. Signal voltage will vary from .2-.74 volt at idle to above 4 volts at wide open throttle.

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

DTC 22 will set if:
^ The ignition key is "ON."
^ TP sensor signal voltage is less than .2 volt for 4 seconds.

Test Description: Number(s) below refer to circled number(s) on the diagnostic chart.

1. With closed throttle ignition "ON," TP sensor voltage should read .2-.74 volt.
2. Simulates DTC 21: (high voltage). If ECM recognizes the high signal voltage the ECM and wiring are OK.
3. Simulates a high signal voltage. Checks CKT 417 for an open.

NOTICE: If DTC 22 is set, the ECM will use a fail-soft value for TP of about 3% throttle angle. The Tech 1 will continue to display actual sensor value.

Diagnostic Aids:

The Tech 1 displays throttle position in volts. Voltage should increase at a steady rate as throttle is moved toward Wide Open Throttle (WOT.)

The Tech 1 also displays throttle angle: 0% = closed throttle, 100% = WOT.

An open or short to ground in CKT 416 or 417 will result in DTC 22 to be set.

Check for:
^ Poor Connection or Damaged Harness. Inspect ECM harness connectors for backed out terminal "YFl3" 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 TP sensor voltage display 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.
^ TP Sensor Scaling. Observe TP sensor voltage display while depressing accelerator pedal with engine stopped and ignition "ON." Display should vary from .2-.74 volt when throttle is closed to over 4 volts when throttle is held at wide open throttle position.