1.
Allow the system to stabilize to ambient tempera-
tures, and compare the bunk and main evapora-
tor temperature sensor values using the tem-
plates in ServicePro. If the two values are
significantly different, continue with step #2 to
confirm the suspected sensor is not reading
properly.
NOTICE
Do not allow the CDTC temperature sensor to get
wet. The circuitry will be damaged.
2.
Remove the sensor and place it in a plastic bag,
them put the bag and sensor in a cup of ice
water.
3.
After the sensor has been in the ice water for ten
minutes, measure the sensor resistance.
The resistance should be approximately 29,190
ohms at 32°F (0°C).See
4.
If the resistance differs significantly, replace the
sensor.
CDTC Temperature Sensor Temperature versus
Resistance
Temp °F (°C)
Resistance (ohms)
32 (0)
29190
42 (6)
22180
53 (12)
17050
64 (18)
13250
75 (24)
10400
86 (30)
8240
96 (36)
6590
107 (42)
5320
113 (45)
4790
Table 11, CDTC Temperature Sensor Temperature
versus Resistance
Calibration Procedure
When the FCU or any actuator motor is replaced, the
system must be recalibrated. The calibration proce-
dure allows the FCU to learn the extreme positions
of the actuator motors for the recirc door, tempera-
ture control door, and the air selection mode door.
Use the following procedure to recalibrate the sys-
tem.
1.
Turn the ignition on, engine off.
2.
Set the blower speed to the off position (all the
way counterclockwise).
3.
Set the air selection switch to full defrost (all the
way clockwise).
4.
Set the temperature control switch to full hot (all
the way clockwise).
5.
Press and hold the A/C and recirc buttons at the
same time until the indicators on the buttons are
both flashing.
When the indicators on the recirc and A/C but-
tons start flashing, the FCU has entered calibra-
tion mode. Calibration takes place automatically
at this point and the blower can be heard operat-
ing. When the unit is finished calibrating, the indi-
cators and blower turn off and the system can be
operated normally.
09/16/2009
f831823
Fig. 12, CDTC Temperature Sensor
f040617
80000
70000
60000
50000
40000
30000
20000
10000
0
0°F
50°F
100°F
150°F
200°F
250°F
Temperature
COTC Temperature Sensor Resistance
Resistance (Ohms)
(−18°C)
(10°C)
(38°C)
(66°C)
(93°C)
(121°C)
06/22/2012
Fig. 13, CDTC Temperature Sensor Temperature vs.
Resistance
Heater and Air Conditioner Troubleshooting
83.00
Electrical System Tests
122SD and Coronado Workshop Manual, Supplement 9, June 2014
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