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

AR49.20-P-2063MFF

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

17.01.2020

Engine

654 in model 118, 177, 247

Modification notes

16.01.2020

Document completely revised.

1

Electrical connector

6

Vent line

11

Electrical line

2

Bolts

7

Screw

12

Vacuum line

3

Electrical line

8

Screw

N37/7

Control unit for NOx sensor upstream of SCR catalytic converter

4

Bracket

9

Cable duct

N37/7b1

NOx sensor upstream of SCR catalytic converter

5

Electrical connectors

10

Bracket

 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

 Caution

Risk of injury caused by scraping or cutting body parts on sharp vehicle parts

Always wear protective gloves when working on or near sharp and non-deburred vehicle parts.
Deburr repair panels.

AS00.00-Z-0017-01A

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

Remove upper engine cover.

AR01.10-P-2405MFF

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

2

Release electrical connections (5) and disconnect.

3

Remove bleed line (6) from cylinder head cover and place to one side.

4

Seal openings with suitable stop plug.

 Record plug

*129589009100

5

Remove electric lines (11) from cable duct (9) and place to one side.

6

Remove vacuum line (12) from cable duct (9).

7

Remove screw (7).

 M61

*BA00.10-P-1002-04A

8

Remove screw (8).

9

Place cable duct (9) to one side.


Do not crush or kink or subject electric lines to tension.
This will result in damage to electric lines and impair their function.

10

Release electrical connector(1) and disconnect.

11

Unscrew bolts (2) and remove NOx sensor control unit upstream of SCR catalytic converter (N37/7) from bracket (10).

 Bolt, NOx control unit to holder

*BA07.04-P-1016-02A

12

Remove electric line (3) from brackets (4).


Do not subject electric line (3) to tension, crush it, or kink it.
This causes damage to the electric line (3) and impairs its function.

13

Remove NOx sensor upstream of the SCR catalytic converter (N37/7b1).

 Installation: Coat thread at NOx sensor upstream of SCR catalytic converter (N37/7b1) 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

14

Remove NOx sensor upstream of SCR catalytic converter (N37/7b1) with NOx sensor control unit upstream of SCR catalytic converter (N37/7).

15

Seal exposed opening with suitable stop plug.

 Record plug

*129589009100

16

Install in the reverse order.



Check

17

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

If NOx sensor upstream of SCR catalytic converter (N37/7b1) with NOx sensor control unit upstream of SCR catalytic converter (N37/7) was replaced.



AD00.00-P-2000-06MFA

18

Read out fault memory and delete if necessary.



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

19

Perform an engine test run; check the engine for leak-tightness and proper function.

20

Install upper engine cover.

AR01.10-P-2405MFF

 Metric screws/bolts and nuts as per MBN 10 105, 10 143

Number

Designation

8.8

10.9

BA00.10-P-1002-04A

M61

Nm

9

13

 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