Inspection Procedure
HINT:
- If DTC P0441, P0446, P0450 or P0451 is output together with DTC P0442 or P0456, first troubleshoot DTC P0441, P0446, P0450 or P0451. If no malfunction is detected, troubleshoot DTC P0440 next.
- Read freeze frame data using a hand-held tester or OBD II scan tool. Freeze frame data record the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data, from the time the malfunction occurred.
- When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check the vapor pressure sensor.
- Check voltage between terminals VC and E2 of ECM connector.
CHECK:
- Turn the ignition switch to ON.
CHECK:
Measure the voltage between terminals VC and E2 of the ECM connector.
OK: Voltage: 4.5 to 5.5 V
- NG: Replace ECM (See ENGINE CONTROL MODULE (ECM) ).
- OK: Go to next step.
- Check voltage between terminals PTNK and E2 of ECM connectors.
PREPARATION:
- Turn the ignition switch to ON.
CHECK:
Measure the voltage between terminals PTNK and E2 of the ECM connectors.
- Disconnect the vacuum hose from the vapor pressure sensor.
- Using the MITYVAC (Hand-held Vacuum Pump), apply a vacuum of 4.0 kPa (30 mmHg, 1.18 in.Hg) to the vapor pressure sensor.
- Check the vapor pressure sensor output waveform using a hand-held tester.
NOTE: Vacuum applied to vapor pressure sensor must be less than 66.7 kPa (500 mmHg, 19.7 in.Hg).OK:
- Voltage: 2.9 to 3.7 V
- Voltage: 0.5 V or less
- A consecutive waveform presents.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- OK: Check for intermittent problems (See PRE-CHECK ).
- NG: Go to next step.
- Check for open and short in harness and connectors between vapor pressure sensor and ECM (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE
).
- NG: Repair or replace harness or connector.
- OK: Replace vapor pressure sensor.