Check fire extinguishing system temperature sensor

AR86.10-P-0123A

Check fire extinguishing system temperature sensor

30.4.09



Checking

1

Check system components of fire extinguishing system for electrical continuity

 Switch on ignition, perform acoustic test and switch ignition back off.

After switching on ignition the following system components are checked for continuity:
- extinguishing agent tank 1 squib (R42) and extinguishing agent tank 2 squib (R42/1)

- Extinguishing agent tank 1 pressure monitoring switch (S62/27) and extinguishing agent tank 2 pressure monitoring switch (S62/28)

- Rear fire extinguishing system temperature sensor (B65/1) and engine fire extinguishing system temperature sensor (B65)

 If the specified value is not achieved for at least one of the system components specified above, the fire extinguishing agent system warning buzzer sounds for approx. 10 H13

All of the system components are possible causes.

2

Disconnect extinguishing agent tank 1 pressure monitoring connector (S62/27x1) and extinguishing agent tank 2 pressure monitoring connector (S62/28x1) jumper their poles on wiring harness side,

 So that their status does not influence actuation of the fire extinguishing system warning buzzer (H13).
Connect the section on the wiring harness side to the fire extinguishing system control unit (N100).

3

Disconnect electrical connector from extinguishing agent tank 1 squib (R42x1) and electrical connector from extinguishing agent tank 2 squib (R42/1x1) and jumper their two poles at side of wiring harness,

 So that their status does not influence actuation of the fire extinguishing system warning buzzer (H13).
Connect the section on the wiring harness side to the fire extinguishing system control unit (N100).

4

Check rear fire extinguishing system temperature sensor (B65/1) and engine fire extinguishing system temperature sensor (B65) for continuity

 Switch on ignition, perform acoustic test and switch ignition back off.

If the fire extinguishing system warning buzzer (H13) no longer sounds, the rear fire extinguishing system temperature sensor (B65/1) and the engine fire extinguishing system temperature sensor (B65) are OK

If the fire extinguishing system warning buzzer (H13) sounds, check rear fire extinguishing system temperature sensor (B65/1) and engine fire extinguishing system temperature sensor (B65).

5

Remove fire extinguishing system control unit (N100) from rear wall

 Do not disconnect connector (1) from fire extinguishing system control unit (N100).

AR86.10-P-0101A

6

Remove the cover from the connector (1) and jumper connection pins 12 and 14

 Do not disconnect connector (1) from fire extinguishing system control unit (N100).

7

Confirm rear fire extinguishing system temperature sensor (B65/1) and engine fire extinguishing system temperature sensor (B65) as fault cause

 Switch on ignition, perform acoustic test and switch ignition back off.

If the fire extinguishing system warning buzzer (H13) no longer sounds, check rear fire extinguishing system temperature sensor (B65/1) and engine fire extinguishing system temperature sensor (B65) and continue with step 8.

If the fire extinguishing system warning buzzer (H13) sounds, continue test as of step 10.

8

Disconnect connector (1) from fire extinguishing system control unit (N100)

9

Check rear fire extinguishing system temperature sensor (B65/1) and engine fire extinguishing system temperature sensor (B65) for continuity.

 For this purpose check connection pins 12 and 14 on connector plug (1) for continuity

If the test result is positive, the rear fire extinguishing system temperature sensor (B65/1) and engine fire extinguishing system temperature sensor (B65) are OK.

If there is no continuity, replace rear fire extinguishing system temperature sensor (B65/1) and engine fire extinguishing system temperature sensor (B65) one after another until continuity is present.



Remove/install fire extinguishing system temperature sensor

AR86.10-P-0102A

10

Check wiring harness for damage, discontinuity and correct contact, replace if necessary

 Perform operation step only in event of negative test result in step 7

 Observe:

It is necessary to check the lines on all fire extinguishing system components tested for discontinuity.

11

Check system components of fire extinguishing system for electrical continuity

 Switch on ignition, perform acoustic test and switch ignition back off.

During this test, return the fire extinguishing system to the normal operating state as in Step 1, i.e. reconnect all electrical connectors.

If the fire extinguishing system warning buzzer (H13) continues to sound, first perform steps 2 to 9 again with the certainty that there is no fault in the wiring harness. If, with step 7, the fire extinguishing system warning buzzer (H13) still sounds, continue with step 12.

12

Replace fire extinguishing system control unit (N100)

AR86.10-P-0101A

13

Check system components of fire extinguishing system for electrical continuity

 Switch on ignition, perform acoustic test and switch ignition back off.

During this test, return the fire extinguishing system to the normal operating state as in Step 1, i.e. reconnect all electrical connectors.

If the fire extinguishing system warning buzzer (H13) still sound, perform steps 2 to 9 again, with the certainty that there is no fault in the wiring harness and the fire extinguishing system control unit (N100).

14

Return fire extinguishing system to operating state

15

Check system components of fire extinguishing system for electrical continuity

 Switch on ignition, perform acoustic test and switch ignition back off.

If the fire extinguishing system warning buzzer (H13) still sounds, one of the other system component is defective.