SCR sensor replacement (SCR VERSIONS ONLY)

Warning

The NOx sensors are identical, the Upstream and Downstream sensors0 can be distinguished by their assembly position on SCR (Upstream = SCR Input | Downstream = SCR Output).
This position allows distinguishing also the connection of the SCR wiring (D1 > SCR Input = 5-pin connector | D2 > SCR Output = 4-pin connector).
The NOx sensors can be without Upstream and Downstream identification label (SCR Input/Output).
The NOx sensors supplied as spare parts are without Upstream and Downstream identification label (SCR Input/Output). After assembly, mark them for a future identification (GREEN = SCR Input | YELLOW = SCR Output).
The connectors on the SCR wiring for the connection of the AdBlue® injector and SCR-T are identical, mark the connectors in order to tell them apart and avoid inverting the connection upon assembly.

6.15.1 SCR-T

6.15.1.1 Disassembly

1 - Disengage connector A.

2 - Unscrew and remove SCR-T sensor B.

6.15.1.2 Assembly

1 - Screw SCR-T sensor B on SCR C.

2 - Tighten SCR-T sensor B to SCR C (tightening torque of 45 Nm).

3 - Fit connector A to SCR-T sensor B.

Fig. 6.76

6.15.2 NO_x

6.15.2.1 Disassembly

1 - Disengage connectors D1 and D2.

2 - Loosen screws E and remove SCUs F.

3 - Loosen and remove NOx sensors G from SCR C.

6.15.2.2 Assembly

1 - Screw NOx sensor G on SCR C.

2 - Tighten NOx sensors G to SCR C (tightening torque of 60 Nm).

3 - Fasten SCUs F with screws E (tightening torque of 3 Nm).

4 - Fit connector D1 and D2 as described in the connection plates (D1 > Upstream = 5-pin connector | D2 > SCR Downstream = 4-pin connector).

Fig. 6.77

Fig. 6.78

Fig.6.79

1 General information