Mazda Training manual — part 22

Powertrain Engines

Diesel Particulate Filter System

•

The DPF is a honeycomb structure with many channels closed off at alternate ends. The
soot particulates contained in the exhaust gas accumulate at the porous dividing walls,
while gaseous components such as CO and HC pass through the filter with no problem.

•

To prevent the filter becoming blocked with soot particulates, it must be ‘regenerated’ at
certain intervals, i.e. the collected soot particulates are burnt off. In order to facilitate the
regeneration process, the channels of the DPF feature a catalytic coating that lowers the
temperature required to burn off the soot particulates.

L1001.4_01147

1 Soot

2 Catalytic

coating

•

Pressure and temperature sensors in the DPF detect when the soot accumulation
capacity of the filter is reached. Then the engine control system increases the exhaust
gas temperature by multiple fuel injections to burn off the particulates.

Curriculum Training

01-75

Engines Powertrain

Service Procedures

Replacing the Engine Oil

•

Every time the engine oil is replaced, the parameter “Calculated oil dilution” in the PCM
must be reset with the aid of M-MDS (Mazda-Modular Diagnostic System). To perform
the procedure select the option Toolbox

ÆPowertrainÆData ResetÆEngine Oil and

follow the instructions of M-MDS.

Injection Amount Learning Function

•

The injection amount learning function is used to compensate the deviations in the
injection amount due to mechanical wear of the injectors, achieving a smooth engine
operation. The injection amount correction function is carried out by the PCM under
specific conditions. In addition, the injection amount learning function has to be carried
out at specified service intervals by means of M-MDS. To perform the procedure select
the option Toolbox

ÆPowertrainÆEngine ChecksÆLearningÆInjection Amount

Correction and follow the instructions of M-MDS.

NOTE: The injection amount learning function is performed several times at a pressure of

35 MPa, 65 MPa, 100 MPa and 140 MPa. As a result, slight changes in engine
sound are normal.

NOTE: The injection amount learning function will be aborted, if the idle fluctuations of the

engine are too high (e.g. due to a faulty injector).

01-76 Curriculum

Training

Powertrain Engines

DPF Manual Regeneration

•

If the DPF indicator light is illuminated and the DPF is blocked due to an excessive soot
amount accumulated, it must be manually regenerated with the aid of M-MDS. To
perform the procedure select the option Toolbox

ÆPowertrainÆDPFÆDPF

Regeneration and follow the instructions of M-MDS.

•

Depending on the amount of soot accumulated in the DPF the PCM automatically
selects normal regeneration mode (34 min) or long regeneration mode (60 min).

•

In order to cancel the manual regeneration process perform the following procedure:

1. Depress the clutch pedal, shift to 1st gear and verify that the engine speed

decreases to idle speed (manual regeneration is cancelled).

2. Shift to Neutral and increase the engine speed to 3000 min

-1

for 1 min (DPF is

cooled).

3. If the manual regeneration must be performed again, wait for approx. 5 min before

re-starting the regeneration process.

NOTE: Always perform the manual regeneration in a well ventilated place and use an

appropriate exhaust-gas extraction system. The vehicle should also not be stationed
in front of any flammable or low heat resistant material, since high temperature
exhaust gas is emitted during this process. In addition, the hood should be opened to
prevent the engine from overheating. Do not apply electrical load (such as turning on
the headlights or rear window defroster) during manual regeneration, since the post
injection amount is changed and regeneration may not be performed correctly.

NOTE: If the exhaust gas temperature during manual regeneration exceeds a certain limit,

the PCM stops the regeneration process and increases the engine speed to
2500 min

-1

to cool the DPF.

NOTE: Depending on the amount of soot accumulated the PCM performs normal and long

regeneration mode one after another, i.e. the regeneration process may take up to
94 min. If the DPF indicator light does not extinguish after the manual regeneration is
finished, perform the regeneration process again.

Curriculum Training

01-77

Engines Powertrain

WL-C Engine

•

The WL-C engine with 2.5 L displacement (also termed as 2.5 MZR-CD engine) is fitted
in the BT-50 models. It is equipped with a common rail direct injection system and a VGT
turbocharger.

Mechanical

Features

•

The mechanical system of the WL-C engine has the following features:

–

Gear and belt driven 16 valve DOHC engine

–

Balancer shafts

–

Valve train with automatic timing belt tensioner and adjustable roller cam followers

–

Vacuum pump and power steering oil pump driven by the timing gears

–

V-belt drive with three belts and two manual tensioners

01-78 Curriculum

Training