Change data record in engine control (MR) control unit

SM07.54-W-0002A

Change data record in engine control (MR) control unit

15.9.09

Category

Op. no.

Operation text

Time

Acc. no.

Code

O

027062

OPERATIONS: CHANGE DATA RECORD AND SOFTWARE IN MR CONTROL UNIT

0,7h

07 950 55

Gaseous fuel engine

O

027063

OPERATIONS: REPLACE CAP OF ELECTRONIC ACCELERATOR ADJUSTING MOTOR

0.1 h

07 950 55

Gaseous fuel engine

O

027064

OPERATIONS: CHECK INSTALLATION OF LINES OF OXYGEN SENSOR

0.1 h

07 950 55

Gaseous fuel engine

O

027065

OPERATIONS: REPAIR INSTALLATION OF LINES OF OXYGEN SENSOR

0.1 h

07 950 55

Gaseous fuel engine

O

027066

OPERATIONS: CHECK GAS INJECTION VALVES

0.8 h

07 950 55

Gaseous fuel engine

O

027067

OPERATIONS: MODIFY GAS INJECTION VALVE (1)

0.4 h

07 950 55

Gaseous fuel engine

O

027068

OPERATIONS: MODIFY GAS INJECTION VALVE (EACH REMAINING)

0.2 h

07 950 55

Gaseous fuel engine



Checking

1

Close gas shutoff valves at compressed-gas tanks

AR47.10-W-0005H

 Danger!

Risk of accident caused by vehicle starting off by itself when engine is running. Risk of injury caused by contusions and burns during starting procedure or when working near the engine as it is running

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

AS00.00-Z-0005-01A

2

Start engine and run on idle until the engine goes off by itself

 In this way residual gas is used up in the lines and components.

3

Switch off ignition

4

Remove cylinder head cover (3)

AR01.20-W-5014H

5

Check part number of gas injection valves

 Gas injection valves, which do not have the part number A 906 078 04 49, should be replaced:



Replace gas injection valve.

AR07.54-W-0003H

 With regard to return shipment or scrapping of removed parts, please observe the information in your warranty system.

6

Check gas injection valves for firm seating in intake manifold

 If loose gas injection valves are detected:



Remove corresponding gas injection valve, insert shim in the valve seat and install gas injection valve again.

AR07.54-W-0003H

7

Install cylinder head cover (3)

 Only tilt back the cab after checking the installation of lines of oxygen sensor.

AR01.20-W-5014H

8

Open gas shutoff valves on compressed-gas tanks

AR47.10-W-0005H

9

Replace cap (4) on electronic accelerator adjusting motor

10

Check routing of electrical line (1) to oxygen sensor

 If the installation of lines does not correspond to the figure or the insulation of the electrical line (1) is damaged:



Insulate electrical line (1), route over the intake manifold (6) and secure with cable ties (2).

 Danger!

Risk of injury caused by body parts being pinched or crushed as cab is tilted

Ensure that no one is within the tilting range of the cab as it is being tilted. Always tilt the cab all the way to the end position and secure with the safety strut.

AS60.80-Z-0001-01A

11

Lower cab



Notes on tilting the cab

AH60.80-N-0003-01A

12

Close maintenance flap

13

Connect Star Diagnosis

 The download is available as of Star Diagnosis DAS update 11/2009.

 The following conditions must be met for carrying out the download:

- Battery voltage 24 V...26 V.

- It is essential that the power supply for the STAR DIAGNOSIS computer remains constant throughout the entire period.

During the download, do not

- Start any other application,

- Perform on-board diagnosis,

- Run or start the engine and

- Disconnect the vehicle battery.

14

Switch on ignition

15

Start Diagnosis Assistance System (DAS)

16

Select "Truck" category

17

Select "Automatic access using model series"

18

Select "Special functions"

19

Select "CNG [compressed natural gas] download"

20

Select the download with the highest number

 The download is menu-assisted. Follow all of the instructions given by the Diagnosis Assistance System (DAS).

With the display "The control unit already contains the latest control unit software version" the latest version is already installed and the process is complete.

Likewise the process is complete if the display
"The control unit programming has been carried out successfully." appears.

21

Disconnect Star Diagnosis

Part no.

Designation

Quantity

A 906 078 04 49

Gas injection valve

As required

A 126 262 10 52 05

Washer

As required

A 000 998 69 21 05

Cap

1