What does it mean?
This diagnostic code (DTC) is a generic powertrain code, meaning it applies to vehicles equipped with OBD-II. Although generic, specific repair steps may vary by brand/model.
The EVAP (Evaporative Emissions) system purges fuel tank vapors into the engine and burns them instead of releasing them into the atmosphere as harmful emissions. The EVAP system contains a pressure sensor to check system integrity.
Periodically, the EVAP system performs a pressure test to ensure there are no leaks in the system. It uses this sensor, also known as the Fuel Tank Pressure (FTP) sensor, to check for leaks. Essentially, P0453 means the PCM (Powertrain Control Module) has detected that the EVAP or FTP sensor indicates higher than normal pressure (above 4.5 volts) in the EVAP system. NOTE: On some vehicles, the FTP is part of the fuel pump in the tank.
Related evaporative emission fault codes include P0450, P0451, P0452, P0454, P0455, P0456, P0457, P0458, and P0459.
Potential Symptoms
There will likely be no noticeable symptoms with this code other than the MIL (Malfunction Indicator Lamp), commonly referred to as the check engine light. However, there may be noticeable fuel odors in some cases.
Causes
A P0453 DTC fault code can be caused by one or more of the following:
Open circuit in the FTP sensor signal wire
Short to voltage in the FTP sensor signal wire
Faulty FTP sensor
Abnormally high pressure in the fuel tank due to clogged EVAP purge lines or overfilling the tank
Loose/damaged FTP sensor connector
Loss of ground to the sensor
Possible Solutions
Using a scan tool, access the FTP sensor value with the Key On Engine Off (KOEO). The normal value is typically around 2.5 volts at atmospheric pressure (may fluctuate due to altitude). It should never exceed 4.5 volts.
1) If it is near 2.7 V with the gas cap closed, the problem is likely intermittent. Using a digital voltmeter, measure the voltage on the signal wire while trying to induce the issue by testing the entire FTP sensor wiring. If the voltage fluctuates during wiggle tests, check for connector issues; i.e., water in the connector, broken or chafed wiring.
2) If the value shown on the scan tool is above 4.5 V, disconnect the sensor (if possible) and check the voltage again. If the high voltage is still present when disconnected, inspect the wiring harness for a short to voltage on the signal wire. If the high voltage disappears when the sensor is disconnected, check for proper sensor grounding and appropriate reference voltage. If you have good ground and 5-volt reference voltage, replace the FTP sensor as it is likely shorted.
Other EVAP DTCs: P0440 – P0441 – P0442 – P0443 – P0444 – P0445 – P0446 – P0447 – P0448 – P0449 – P0452 – P0455 – P0456