Eugenio,77
mail@toyota-club.net
© Toyota-Club.Net
Oct 2019

Particle emission limits for gasoline direct injection engines were first introduced in the regulations Euro 5a (PM) and Euro 6b (PN). To meet the current Euro 6d PN requirements, GDI engines should obtain a particulate filter (GPF).


GPF is a ceramic structure of channels alternately closed on one or the other side, integrated in the exhaust pipe. As gases pass through the porous walls of the channels, solid particles and ash are deposited on their surface. GPF regeneration is passive: when the driving mode allows the filter to be sufficiently heated, the fuel supply is cut off, and clean air flows through cylinders into the exhaust, and the oxygen of the air oxidizes the accumulated soot particles.


Particulate filters for diesel engines (DPF) are well known already, but automotive science says do not directly compare them with gasoline filters due to significant differences.
- The accumulation of soot in GDI is much slower (since the content of particles is about five times (PM) or ten times (PN) lower than in diesel engines).
- The maximum temperature of exhaust gases in GDI is almost two times higher (which radically simplifies regeneration without various tricks necessary for diesels).
- Even despite a significantly lower concentration of oxygen in the exhaust gases of a gasoline engine.
- In GPF, the main role in particle capture is played by filter material, not layered soot, although ash deposits also improve filtration efficiency.
- Physical cleaning of GPF is not provided.
- Gasoline engines are more sensitive to exhaust backpressure.
- Resource tests show that uing of low-SAPS motor oils is not necessary for GPF (the main share in ash deposits is iron oxide - wear products).


The state of the filter is monitored using a differential pressure sensor (between the atmosphere and the exhaust upstream of GPF).

1 - differential pressure sensor, 2 - ECM, 3 - combination meter, 4 - catalyst, 5 - particulate filter (GPF), 6 - air-fuel ratio sensor, a - atmosphere

If for a long time the driving conditions do not allow to warm up the filter and start regeneration, then the soot accumulation becomes excessive. Upon reaching certain thresholds, the system will display an invitation to service, then turn on the malfunction indicator and begin to limit engine power.

A - message "Exhaust Filter Full Visit Your Dealer", possible power limitation; B - message "Exhaust Filter Full Visit Your Dealer", MIL is ON, possible power limitation; C - message "Exhaust Filter Full Visit Your Dealer", MIL is ON, mandatory power limitation

Since the implementation of GPF a several new items were added in the familiar list of engine management system trouble codes.

SAE DTC	Toyota DTC	Code	Cause
P244B	P244B00	Particulate filter differential pressure too high (B1)	- GPF (front exhaust pipe) - Differential pressure sensor (B1) - Mass air flow sensor - Wire harness or connector - ECM
P2454	P245211	Particulate filter pressure sensor A - circuit short to ground	- Differential pressure sensor (B1) - circuit - Differential pressure sensor (B1) - ECM
P2455	P245215	Particulate filter pressure sensor A - circuit short to battery / open	- Differential pressure sensor (B1) - circuit - Differential pressure sensor (B1) - ECM
P2453	P24521C	Particulate filter pressure sensor A - circuit voltage out of range	- Vacuum transmitting hose - Differential pressure sensor (B1)
P2453	P24522A	Particulate filter pressure sensor A - signal stuck in range	- Differential pressure sensor (B1) - circuit - Differential pressure sensor (B1) - Vacuum transmitting hose - Vacuum transmitting pipe - ECM
P2460	P245E11	Particulate filter pressure sensor B - circuit short to ground	- Differential pressure sensor (B2) - circuit - Differential pressure sensor (B2) - ECM
P2461	P245E15	Particulate filter pressure sensor B - circuit short to battery / open	- Differential pressure sensor (B2) - circuit - Differential pressure sensor (B2) - ECM
P245F	P245E1C	Particulate filter pressure sensor B - circuit voltage out of range	- Vacuum transmitting hose - Differential pressure sensor (B2)
P245F	P245E2A	Particulate filter pressure sensor B - signal stuck in range	- Differential pressure sensor (B2) - circuit - Differential pressure sensor (B2) - Vacuum transmitting hose - Vacuum transmitting pipe - ECM
P2463	P246300	Particulate filter restriction - soot accumulation (B1)	- GPF (front exhaust pipe)
P2465	P246500	Particulate filter differential pressure too high (B2)	- GPF (front exhaust pipe) - Differential pressure sensor (B2) - Mass air flow sensor - Wire harness or connector - ECM