Check extinguishing agent tank pressure monitoring switch

AR86.10-P-0122A

Check extinguishing agent tank pressure monitoring switch

30.4.09

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Checking

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Notes for extinguishing agent tank pressure monitor switch

AH86.10-P-0001-03A

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 (H13) sounds for approx. 10 s.

All of the system components are possible causes.

2

Disconnect electrical connectors from extinguishing agent tank 1 squib (R42x1) and electrical connectors from extinguishing agent tank 2 squib (R42/1x1) and jumper their two 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

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

4

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).

 Jumpering disconnects the rear fire extinguishing system temperature sensor (B65/1) and engine fire extinguishing system temperature sensor (B65), so their status has no longer any effect on the actuation of the fire extinguishing system warning buzzer (H13).

5

Check extinguishing agent tank 1 pressure monitoring switch (S62/27) and extinguishing agent tank 2 pressure monitoring switch (S62/28) 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 extinguishing agent tank 1 pressure monitoring switches (S62/27) and extinguishing agent tank 2 pressure monitoring switch (S62/28) are ok and require checking.

If the fire extinguishing system warning buzzer (H13) sounds, the extinguishing agent tank 1 pressure monitoring switches (S62/27) and extinguishing agent tank 2 pressure monitoring switch (S62/28) must be checked.

6

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.

 Connect the section on the wiring harness side to the fire extinguishing system control unit (N100).

7

Confirm extinguishing agent tank 1 pressure monitoring switch (S62/27) and extinguishing agent tank 2 pressure monitoring switch (S62/28) 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 extinguishing agent tank 1 pressure monitoring switches (S62/27) and extinguishing agent tank 2 pressure monitoring switch (S62/28) and continue with step 8.

If the fire extinguishing system warning buzzer (H13) sounds, continue test as of step 12.

8

Reconnect extinguishing agent reservoir pressure monitor connector 1 (S62/27x1)

 The extinguishing agent tank 2 pressure monitoring connector(S62/28x1) remains disconnected and jumpered.

9

Check extinguishing agent reservoir pressure monitoring switch 1 (S62/27) for electrical continuity

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

If the fire extinguishing system warning buzzer (H13) does not sound, the extinguishing agent tank 1 pressure monitoring switch (S62/27) is okay.

If the fire extinguishing system warning buzzer (H13) sounds, the extinguishing agent tank 1 pressure monitoring switch (S62/27) is defective and must be replaced together with the extinguishing agent tank 1. 

Remove/install extinguishing agent tank

AR86.10-P-0100A

 Repeat continuity test with new extinguishing agent tank 1 pressure monitoring switch (S62/27).

10

Reconnect extinguishing agent reservoir pressure monitor connector 2 (S62/28x1)

11

Check extinguishing agent reservoir pressure monitoring switch 2 (S62/28) for electrical continuity

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

Evaluate test result for extinguishing agent tank 2 pressure monitoring switch (S62/28) analog to Step 9.

12

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.

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) continues to sound, perform steps 2 to 11 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 sound, proceed with step 14.

14

Replace fire extinguishing system control unit (N100)

AR86.10-P-0101A

15

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, again perform steps 2 to 11, with the certainty that there is no fault in the wiring harness and in the fire extinguishing system control unit (N100).

16

Return fire extinguishing system to operating state

17

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) continues to sound, one of the other system components is defective:


Check extinguishing agent tank squib

AR86.10-P-0121A

Check fire extinguishing system temperature sensor

AR86.10-P-0123A