Fault Message:

SHORT - INLET PRESS SENSOR/EXC WRG

Fault Code:

4960181APU

Associated CAS:

None

The Inlet Pressure Sensor excitation load resistance read by the Full-Authority Digital Engine-Controller (FADEC) is out of range low. This shows a possible short in the Inlet Pressure Sensor excitation or the engine branched wiring-harness.

• Auxiliary Power Unit (APU) Full-Authority Digital Engine-Controller (FADEC) (A108)
• Inlet Pressure Sensor (MT1)
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

1. Examine the engine branched wiring-harness for bare wiring, kinks, worn areas and other damage (WM 49-12).

   1. If there is bare wiring, kinks, worn areas or other damage, go to step 6.
   2. If NO, continue with next step.

2. Examine the inlet pressure sensor (MT1) receptacle for contamination and damage.

   1. If contaminated or damaged, go to step 7.
   2. If NO, continue with next step.

3. Perform a continuity check within the inlet pressure sensor (MT1) receptacle as follows:

   From	To	Expected Result	Result
   MT1P1-C	MT1P1-D	>20 ohms

   1. If checks are not good, go to step 7.
   2. If checks are good, continue with next step.

4. Perform a wiring check between P802 (APU) and MT1P1 (inlet pressure sensor).

   1. If wiring checks are not good, go to step 6.
   2. If wiring checks are good, continue with next step.

5. Perform a wiring check between J802 (AC wiring harness) and A108AP1 (FADEC).

   1. If wiring checks are not good, repair defective wiring as required and do close out.
   2. If wiring checks are good, continue with next step.

6. Replace Engine branched wiring-harness.

   1. If system checks are good, do close out.
   2. If fault remains, continue with next step.

7. Replace the inlet pressure sensor (MT1).

   1. If system checks are good, do close out.
   2. If fault remains, continue with next step.

8. Replace FADEC (A108).
9. Do close out.