Test Point 11

TEST POINT 11
A/C Signal Implausible

DTC 30

Note:
This fault can be determined only during the system test.

Signal Implausible

1. Check refrigerant.

2. Check high/low pressure switch.

Battery positive voltage must be present at terminal 1 on the high/low pressure switch (with ignition on) if there is enough refrigerant in the system.

3. Check heating activation relay.

Battery positive voltage must be present at terminal 87 if the ignition is switched on.

4. Check the air conditioning compressor relay.

Battery positive voltage must be present at terminal 30 (with the ignition on) and high/low pressure switch actuated.

Ground must be connected to terminal 31.

Battery positive voltage must be connected to terminal 86 when the engine is started.

Ground must be connected to terminal 85 when the DmE switches on the air conditioning compressor (7 seconds delay).

5. Pull off connector D on the heating/air conditioning control.

6. Pull off the DmE connector.

7. Connect ohmmeter to D-6 and DmE connector pin 69.

Display: < 5 ohms

Note:
The wire is routed via two plug connections.

8. Pull off the air conditioning compressor relay.

9. Connect ohmmeter to terminal 85 and DmE connector pin 62.

Display: < 5 ohms

Note:
The wire is routed via one plug connection.