APU OIL TEMP HIGH
(Caution)

Oil temperature greater than 325°F. For ground operation, this failure triggers a protective shut-down. For flight operation, the shut-down is inhibited.

• The ESU has determined that the sensed oil temperature from the oil temperature transducer is out of specifications.

• APU Oil Temp Sensor (RT01)
• APU Oil Temp Sensor Connector
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

1. Verify oil system servicing. If the oil is close to 800 hours, drain, and service.
2. Check the oil temperature sensor resistance by ringing from A39AP1 pins 4C to 4D, compare reading and cross check against oil temperature using the following table:
   

   °C	Resistance	°C	Resistance
   -70	68.27 ± 0.50	60	112.28 ± 0.50
   -60	71.19 ± 0.50	70	116.27 ± 0.50
   -50	74.24 ± 0.40	80	120.36 ± 0.50
   -40	77.39 ± 0.40	90	124.55 ± 0.50
   -30	80.56 ± 0.40	100	128.85 ± 0.50
   -20	83.77 ± 0.40	110	133.26 ± 0.50
   -10	87.04 ± 0.40	120	137.78 ± 0.60
   0	90.38 ± 0.40	130	142.40 ± 0.60
   10	93.80 ± 0.40	140	147.11 ± 0.60
   20	97.31 ± 0.40	150	151.91 ± 0.60
   30	100.91 ± 0.40	200	177.95 ± 1.00
   40	104.60 ± 0.40	250	208.00 ± 1.00
   50	108.39 ± 0.40	300	242.70 ± 1.5

3. If the sensor is out of limits from the table, check and repair wiring/remove and replace RT01.
   Select an MDC Fault Code/Message:B3-006355 - OIL PRESS LOW [APU]