P0450

DTC P0450 EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE SENSOR/SWITCH

MONITOR DESCRIPTION

DTC Detection Condition:

DTC P0450 or P0451 is recorded by the ECM when the vapor pressure sensor malfunctions.

Monitor Strategy:

Typical Enabling Conditions:

Typical Malfunction Thresholds:

P0450
The ECM detects pressure in the fuel tank using the vapor pressure sensor. The ECM supplies the sensor with a regulated 5 V reference voltage and the sensor returns a signal voltage between 0.5 V and 4.5 V according to the pressure level in the fuel tank.

If the output voltage of the vapor pressure sensor is out of the normal range, the ECM will determine that there is a malfunction in the sensor or sensor circuit.

When the pressure indicated by the vapor pressure sensor deviates below -3.999 kPa (-30 mmHg, -1.18 in.Hg) or above 1.999 kPa (15 mmHg, 0.59 in.Hg), the ECM interprets also this as a malfunction in the vapor pressure sensor. The ECM will turn on the MIL and a DTC will be set.

Wiring Diagram:

Typical Malfunction Thresholds:

Step 2 - 3:

INSPECTION PROCEDURE

HINT:
- If DTC P0441, P0446, P0450 or P0451 is output after DTC P0442, first troubleshoot DTC P0441, P0446 P0450 or P0451. If no malfunction is detected, troubleshoot DTC P0442 next.
- Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, this is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.

CHECK FOR INTERMITTENT PROBLEMS

Hand-held tester only:
Inspect the vehicle's ECM using check mode. Intermittent problems are easier to detect when the ECM is in check mode. In check mode, the ECM uses 1 trip detection logic, which has a higher sensitivity to malfunctions than normal mode (default), which uses 2 trip detection logic.

a. Clear the DTCs.
b. Change to check mode.
c. Perform a simulation test.
d. Check the connector and terminal.
e. Wiggle the harness and connector.