ford Workshop Repair Guides

Ford C-MAX Workshop Service and Auto Repair Manuals

309-00 Exhaust System|Removal and Installation > < 309-00 Exhaust System|Specifications
Exhaust System - Exhaust System C-MAX 2003.75 (06/2003-)
Description and Operation

Fuel Borne Diesel Particulate Filter System

The fuel borne diesel particulate filter system consists of the following components:

  • Diesel particulate filter (DPF)
  • Pressure differential sensor
  • Temperature sensor
  • Fuel additive system

DPF

The DPF reduces the pollution generated by diesel vehicles by filtering soot particles out of the exhaust gases.

Pressure Differential Sensor

The pressure differential sensor monitors the pressure drop within the DPF.

Temperature Sensor

The temperature sensor is incorporated to monitor the temperature within the DPF and sends a signal to the powertrain control module (PCM).

Fuel Additive System

The fuel additive system consists of a fuel additive system module and a fuel additive tank with a dosing pump.
For additional information, refer to: Fuel Tank and Lines (310-01 Fuel Tank and Lines, Description and Operation).

Regeneration of the DPF

NOTE:
NOTE:Soot particles can accumulate in the exhaust tailpipe. This is an inherent by-product of the regeneration process and should not be considered a concern.
NOTE:
NOTE:During regeneration it is possible that white smoke may be emitted from the exhaust tailpipe. This is an inherent by-product of the regeneration process and should not be considered a concern.

The pressure differential sensor is connected to the DPF by the pressure differential sensor lines to monitor the pre-pressure and post-pressure of the DPF. The pressure differential sensor converts these measurements to a signal voltage, which is then sent to the PCM to be used as part of the decision of whether to apply the regeneration process or not.

The PCM will choose the optimum time for the regeneration of the DPF. Under normal operating conditions the regeneration process occurs when the PCM has calculated that the DPF requires regeneration and that predetermined vehicle conditions are met (for example, coolant temperature, vehicle speed and engine load).

The engine management system will then close the exhaust gas recirculation (EGR) valve and actuate the turbocharger. This will then generate more engine load and the exhaust gas velocity is reduced. Then, with the aid of the fuel additive and post injection, the soot particles are burnt.
For additional information, refer to: Fuel Tank and Lines (310-01 Fuel Tank and Lines, Description and Operation).

Following regeneration there is an ash residue left in the DPF. Due to this ash residue the DPF must be serviced every 120,000 km.

Manual regeneration of the DPF

If the DPF becomes blocked the pressure differential sensor will register a high pressure diagnostic trouble code (DTC) with the PCM, the malfunction indicator lamp (MIL) will be illuminated and the limp home mode activated.

A blocked DPF can be a result of:

  • Excessive soot particles production
  • Multiple failed regeneration events
  • Mechanical or electrical failure of a related system or sub-system (for example, EGR valve stuck open, charge air system leak, fuel injectors)

The manual regeneration of the DPF can be used to clear the soot particles from the DPF. For additional information, refer to WDS.

1.6L Duratorq – TDCi (DV) DPF

 
Item
Part Number
Description
1
-
Temperature sensor
2
-
Catalytic converter
3
-
Pressure differential sensor
4
-
DPF
5
-
Pressure differential sensor lines

On the 1.6L Duratorq – TDCi (DV) the catalytic converter is above the DPF and is constructed as one assembly.

2.0L Duratorq – TDCi (DW) DPF

 
Item
Part Number
Description
1
-
Temperature sensor
2
-
DPF
3
-
Pressure differential sensor lines
4
-
Pressure differential sensor

On the 2.0L Duratorq – TDCi (DW) the DPF is a separate component from the catalytic converter.

309-00 Exhaust System|Removal and Installation > < 309-00 Exhaust System|Specifications