Check temperature switching points

AR20.40-W-0003A

Check temperature switching points

5.12.06



Checking

 Danger!

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

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

AS60.80-Z-0001-01A



Notes on tilting the cab

AH60.80-N-0003-01A

1

Tilt cab

2

Remove soundproofing on frame at upper left

3

Detach plug for electrical engine cable set (3) on coolant temperature sensor (B65)

4

Connect decade resistor (1) with adapter cable (2) and measuring line (4) to connector for electrical engine cable set (1)

 Set decade resistor (1) to 2 kΩ resistor . This represents a coolant temperature of about 25°C.



*124589096300



*220589009920



*220589009935

5

Connect STAR DIAGNOSIS

6

Switch on ignition

7

Select sector

8

Select "Automatic model series access with quick test"

9

Select engine control (MR) control unit

 STAR DIAGNOSIS now establishes a dialog with the engine control (MR) control unit .

10

Select operational check using actual values

 Display actual values of electromagnetic fan drive.

Display: Coolant temperature 25°C

 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

11

Start engine and run at idling speed

12

Test temperature operating points for electromagnetic fan

 1st switching point:

Set decade resistor (1) to a 240 Ω resistor (200 Ω+30 Ω+10 Ω).

Readout:

- Coolant temperature 89°C

- Status of proportioning valve 3 not active

- Status of proportioning valve 4 not active.

If the proportioning valve 3 or 4 is active, process fault on proportioning valve 3 or 4 with STAR DIAGNOSIS.

The fan turns power.

2nd switching point:

Reduce decade resistor (1) to a 230 Ω resistor (200 Ω+30 Ω).

Readout:

- Coolant temperature 91°C

- Status of proportioning valve 3 active

- Status of proportioning valve 4 not active.

If proportioning valve 3 is not active or proportioning valve 4 is active, process fault on proportioning valve 3 or 4 using STAR DIAGNOSIS.

 The fan must turn at about a half engine speed; replace electromagnetic fan clutch if necessary.

Model 950, 952, 953, 954

AR20.40-W-5616A

Model 930, 932, 933, 934

AR20.40-W-5616G

3rd switching point:

Reduce decade resistor (2) to a 200 Ω resistor.

Readout:

- Coolant temperature 97°C

- Status of proportioning valve 3 active

- Status of proportioning valve 4 active.

If proportioning valve 3 or 4 is not active, process fault on proportioning valve 3 or 4 with STAR DIAGNOSIS.

 The fan must turn at the engine speed; replace electromagnetic fan clutch if necessary.

Model 950, 952, 953, 954

AR20.40-W-5616A

Model 930, 932, 933, 934

AR20.40-W-5616G

13

Stop engine and switch off ignition

14

Remove decade resistor (1), measuring line (2) and adapter cable (4)

15

Plug electrical engine cable set (3) onto coolant temperature sensor (B65)

16

Delete fault memory in engine control (MR) control unit

17

Disconnect STAR DIAGNOSIS

18

Install soundproofing on frame above on the left

19

Lower cab