DTC Confirmation Test "B" (Overall Function Check)
NOTE:
Use the following test to check overall function of STPS circuit. During this test, DTC may not be confirmed.
Malfunction is detected when receives an incorrect voltage from STPS compared to mass airflow, camshaft position sensor and idle air control valve input signals. Possible causes are:
- STPS circuit open or shorted.
- Defective STPS.
- Defective Transmission Control Module (TCM).
WARNING:
Failure to disconnect throttle motor harness connector before touching secondary throttle valve may cause personal injury due to accidental actuation of secondary throttle valve.
CAUTION:
DO NOT use ECM ground terminals when measuring voltage.
To check overall function of STPS circuit, start engine and warm to normal operating temperature. Turn ignition off. Disconnect throttle motor harness connector. See Fig 1. Remove air intake duct. Turn ignition on. Measure voltage between ground and ECM terminal No. 66 by backprobing. See Figure. Check the following:
- With throttle valve fully closed by hand, voltage should be .40-.86 volt.
- With throttle valve fully opened by hand, voltage should be 3.30-3.50 volts.
- Voltage should increase smoothly in response to throttle opening.