# Exhaust gas recirculation – SSP 442 The 1.6ltr. TDI Engine with Common Rail Injection System

> The exhaust gas recirculation module with valve, cooler and exhaust gas flap: design and function; the plastic intake manifold.

- Web page: https://catalog.polo.blue/self-study/ssp-442-16-tdi-common-rail-engine/exhaust-gas-recirculation/
- Original document (PDF): https://cdn.polo.blue/files/SSP442-1.6-TDI-CAYA-CAYB-CAYC-engine.pdf

## Exhaust gas recirculation system

On the 1.6l TDI engine, the exhaust gas recirculation valve and the exhaust gas cooler with exhaust gas flap have been combined into a single module. The advantages of the modular design are a compact space requirement and, at the same time, a shorter control path. The exhaust gas recirculation module is bolted to the exhaust side of the cylinder head and the exhaust manifold. The module is connected to the intake manifold directly through the cylinder head. This allows additional cooling of the recirculated exhaust gases.

![Exhaust gas recirculation system (S442\_212)](https://catalog.polo.blue/instructions/ssp-442/55a8cd3ff6303e84.webp)

### Design

![Design (S442\_242)](https://catalog.polo.blue/instructions/ssp-442/d80ec6764922014b.webp)

### Function

The exhaust gas recirculation helps reduce nitrogen oxide emissions. Part of the exhaust gases are returned to the combustion process. The recirculation quantity is regulated by the engine control unit taking the engine speed, intake air quantity, intake air temperature, injection quantity and air pressure into account.

![Function (S442\_222)](https://catalog.polo.blue/instructions/ssp-442/7ae91b5fec69da87.webp)

****Legend****

- **G39** Lambda probe
- **G62** Coolant temperature sender
- **G69** Throttle valve potentiometer
- **J338** Throttle valve module
- **J623** Engine control unit
- **N18** Exhaust gas recirculation valve
- **N345** Exhaust gas recirculation cooler change-over valve
- **A** Exhaust gas recirculation module
- **B** Vacuum unit
- **C** Catalytic converter

> You will find more information on how the exhaust gas recirculation system works in self-study programme no. 316 “The 2.0l TDI Engine”.

## Intake manifold

The intake manifold is made from plastic. The combination of all exhaust gas recirculation components in the new exhaust gas recirculation module on the exhaust side means there is no separate exhaust gas recirculation valve on the intake manifold. As a result, an aluminium intake manifold is not required.

![Intake manifold (S442\_064)](https://catalog.polo.blue/instructions/ssp-442/8edacdab256a8ece.webp)

> The intake manifold flap motor V157 and the swirl flap adjustment, which it is linked to, currently do not have a function. The intake manifold flap motor V157 and the intake manifold flap potentiometer G336 are currently not included in the self-diagnosis.