Message  Name:

CH A FAULT

Message  Code:

B3-006408

Associated CAS:

AIR COND FAULT
(Advisory)

The channel A of the COMPRESSOR DISCHARGE TEMPERATURE SENSOR is detected failed.

• Compressor Discharge Temperature (CDT) Sensor (MT29)
• Integrated Air System Controller 1 (IASC1) (A55)
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

Fault Confirmation Procedure:

1. Message# = 2
2. Fault Logged = AIR,TAXI
3. Status = FAILED/WIRING
4. Timer = 7
5. Logic = IAS1A-52
6. {Term Definitions}

   1. IAS1A-52 XX 353 00 EXCT XXXX-XXXX XXXX-XXXT XXXX-XXXX 353A:17; COMP DISCHRG TEMP SNSR

1. Use the MDC LRU TEST to view the Integrated Air System Controller (IASC) 1 and IASC 2 TEMPERATURE SENSORS STATUS pages. Compare and record the COMPRESSOR DISCH TEMP value for both IASC.
   
2. Access the Compressor Discharge Temperature Sensor (CDTS) connector (MT29P1). Inspect the connector for proper installation, damage or contaminants.

   1. If defects are found, rectify as required and do close out.
   2. If no defects are apparent, continue with next step.

3. Perform a wiring check between the CDTS (MT29) and IASC 1 (A55) as follows:
   

   From	To	Result
   MT29P1-1	A55P1-26
   MT29P1-3	A55P1-49

   NOTE: Make sure to check for short circuit to ground also.

   1. If wiring defects are found, repair defective wiring as required and do close out.
   2. If no defects are found, continue with next step.

4. Replace the CDTS (MT29). Is the fault still present?

   1. If YES, continue with next step.
   2. If NO, do close out.

5. Interchange IASC 1 with IASC 2 to confirm faulty unit and replace if required.
6. Do close out.