Mazda2 Facelift. Manual - part 7

Engine Diesel 

Engine 

EGR Valve Position Sensor  

• 

The EGRVP sensor is integrated in the DC motor and detects its position by a sliding 
contact potentiometer. When the EGR valve opens the resistance of the potentiometer 
rises. The sensor supplies the PCM with an analogue voltage signal between 0…5V.  

 

 

M2FL_01007 

 

1 

EGRVP sensor  

2 

PCM  

 

Service Training Mazda2 Facelift 

01-7 

Diesel Engine 

Engine 

EGR Cooler  

• 

The EGR cooler is located at the rear side of the engine and is connected to the exhaust 
manifold via the EGR valve. 

 

 

 

 

M2FL_01008 

 

1 EGR 

cooler 

   

 

Intake Shutter Valve  

• 

The ISV (also termed as EGR throttle valve) is driven by a DC motor. It forms a 
restriction in the intake-air system to provide suction to enable EGR. 

 

 

 

M2FL_01009 

 

1 

ISV  

2 

DC motor  

 

01-8 Service 

Training 

Mazda2 

Facelift 

Engine Diesel 

Engine 

• 

The position of the ISV is controlled by the PCM, which activates the DC motor via a 
duty signal.  

 

 

M2FL_01010 

 

1 

From PCM control relay  

3 

PCM  

2 

DC motor  

 

 

 
• 

When the required EGR rate is high the PCM controls the DC motor with a large duty 
cycle. As a result, the ISV closes partly, reducing the cross-section of the intake pipe. 
Thus, a vacuum is generated in the intake manifold and a large amount of exhaust gas 
can be recirculated.  

• 

When the required EGR rate is low the PCM controls the DC motor with a small duty 
cycle. As a result, the ISV opens, making the complete cross-section of the intake pipe 
available. Thus atmosphere or boost pressure is generated in the intake manifold 
(depending on the operating conditions) and only a small amount of exhaust gas can be 
recirculated.  

• 

The PCM controls the DC motor by a duty signal of 0V/12V.  

 
NOTE:  If the ISV system fails, the ISV remains in the open position (by spring force) in which 

no vacuum is produced.  

 

Diagnostics  

• 

The EGR system can be checked as follows:  

– 

monitoring the intake air amount with WDS via the PID (Parameter Identification) 
MAF (g/s) against EGR valve actuation  

– 

monitoring the EGR DC motor with WDS via the PID EGRDC (% duty cycle)  

– 

monitoring the ISV motor with WDS via the PID EGR TV (% duty cycle)  

– 

checking the voltage signal at the EGR DC motor  

– 

checking the voltage signal at the ISV DC motor  

 

Service Training Mazda2 Facelift 

01-9 

Diesel Engine 

Engine 

Glow Plug Control Module  

• 

Since the introduction of EOBD (European On-Board Diagnostics) for Diesel engines, a 
glow plug control module with separate power supply terminals for each glow plug is 
used for the 1.4 MZ-CD Diesel engine of the Mazda2.  

• 

The PCM sends a ground signal to the glow plug control module, which actuates the 
glow plugs accordingly. In addition, the glow plug control module detects the voltage and 
the current output to the glow plugs, and sends a feedback signal to the PCM to facilitate 
failure detection.  

 

 

M2FL_01011 

 

1 

From battery  

3 

Glow plugs  

2 

PCM  

4 

Glow plug control module  

 
• 

The function of the glow plugs can be checked as follows:  

– 

checking the voltage of the glow plugs  

– 

checking the resistance of the glow plugs  

– 

monitoring the glow plug control module with WDS via the PID GPC (On/Off)  

– 

checking the control signal at the glow plug control module  

– 

checking the feedback signal at the PCM  

 
 
 

01-10 Service 

Training 

Mazda2 

Facelift