Remove/install NOx sensor with control unit downstream of SCR catalytic converter

AR49.20-P-2062MFF

Remove/install NOx sensor with control unit downstream of SCR catalytic converter

02.05.2019

Engine

654 in model 118, 177, 247

1

Electrical connector

2

Bolts

3

Electrical line

4

Retaining clips

N37/8

NOx sensor control unit downstream of SCR catalytic converter

N37/8b1

NOx sensor downstream of SCR catalytic converter

 Warning

Risk of burn injuries, suffocation and poisoning when working on the exhaust system and the components connected to it. Risk of suffocation and risk of poisoning caused by inhalation of gaseous and solid components of the exhaust. Risk of poisoning caused by skin contact with solid components of the exhaust.

Wear protective clothing and safety glasses. Use the extraction system. Move people out of the hazard area.

AS49.00-Z-0001-01A

Topical note

Information on preventing damage to electronic components due to electrostatic discharge

AH54.00-P-0001-01A

Topical note

Notes on avoiding damage through contamination and foreign objects

AH00.00-P-5000-01A

 

Remove/install

1

Switch off ignition and store transmitter key outside of transmitter range (min. 2 m).

2

Remove upper engine cover.

AR01.10-P-2405MFF

 Installation: Only install upper engine cover after the leak test.

3

Release electrical connector(1) and disconnect.

4

Remove bolts (2) and remove NOx sensor control unit downstream of SCR catalytic converter (N37/8).

 Bolt, NOx control unit to holder

*BA07.04-P-1016-02A

5

Remove battery carrier.

AR54.10-P-0028MFA

6

Detach electric line (3) from retaining clips (4).


Do not crush, kink or subject electric line (3) to tension.
This will result in damage to electric line (3) and impair its function.

7

Remove NOx sensor downstream of SCR catalytic converter (N37/8b1).

 Installation: Coat thread of NOx sensor downstream of SCR catalytic converter (N37/8b1) with heat-resistant lubricating paste.

 NOx sensor at catalytic converter

*BA07.04-P-1003-02A

Paste, hot lubrication 1 kg, DBL 6879.20

*BR00.45-Z-1005-06A

 Socket

*111589030900

8

Remove NOx sensor downstream of SCR catalytic converter (N37/8b1) with NOx sensor control unit downstream of SCR catalytic converter (N37/8).

9

Clean thread at catalytic converter and at NOx sensor downstream of SCR catalytic converter (N37/8b1) with a rag and check for damage.

If damage is identified



Replace exhaust gas aftertreatment unit and NOx sensor downstream of SCR catalytic converter (N37/8b1) with NOx sensor control unit downstream of SCR catalytic converter (N37/8).

AR49.20-P-1500MFF

10

Seal exposed openings with suitable stop plugs.

 Record plug

*129589009100

11

Install in the reverse order.

12

Read out and delete fault memory.



AD00.00-P-2000-06MFA

13

Adjust software calibration number in CDI control unit (N3/9).

When replacing NOx sensor downstream of SCR catalytic converter (N37/8b1) with NOx sensor control unit downstream of SCR catalytic converter (N37/8).



AD00.00-P-2000-06MFA

 Warning

Risk of accident from vehicle starting off by itself when engine running. Risk of injury (bruises and burns) resulting from working on the engine while it is being started or when it is running.

Secure vehicle to prevent it from starting off by itself. Wear closed and snug-fitting work clothes. Do not touch hot or rotating parts.

AS00.00-Z-0005-01A

14

Perform engine test run and check engine for proper operation and leak tightness.

15

Install upper engine cover.

AR01.10-P-2405MFF

 Sensors

Number

Designation

Engine 654

BA07.04-P-1003-02A

NOx sensor at catalytic converter

Nm

60

 Sensors

Number

Designation

Engine 654

BA07.04-P-1016-02A

Bolt, NOx control unit to holder

Nm

6

Repair materials

Number

Designation

Order number

BR00.45-Z-1005-06A

Paste, hot lubrication 1 kg, DBL 6879.20

A 000 989 76 51