Carrier VECTOR 1550 Series Operation & Service Manual page 188

Alarm
Steps
NO.
P154 CHECK SUPPLY AIR SENSOR

TRIGGER-ON: Sensor reading was not within the expected range during test.

UNIT CONTROL: Pretrip will fail and display "PRETRIP FAIL AND COMPLETED".

RESET CONDITION: Auto Reset if Pretrip is started again, or alarm may be manually reset via key-
pad or by turning the unit off, then back on again.
1 Check Sensor - refer to alarm 123
P155 CHECK COOLANT TEMP SENSOR

TRIGGER-ON: Sensor reading was not within the expected range during test.

UNIT CONTROL: Pretrip will fail and display "PRETRIP FAIL AND COMPLETED".

RESET CONDITION: Auto Reset if Pretrip is started again, or alarm may be manually reset via key-
pad or by turning the unit off, then back on again.
1 Check Sensor - refer to alarm 129
P156 CHECK BYPASS (UNLOADER SOLENOID VALVE) CIRCUIT

TRIGGER-ON: Solenoid coil did not draw expected amperage during test

UNIT CONTROL: Pretrip will fail and display "PRETRIP FAIL AND COMPLETED".

RESET CONDITION: Auto Reset if Pretrip is started again, or alarm may be manually reset via key-
pad or by turning the unit off, then back on again.
1 Check bypass (unloader) solenoid valve - refer to alarm 112
P157 CHECK BATTERY CURRENT

TRIGGER-ON: With all circuits off, current flow of more than 1.5 amps is detected in the electrical cir-
cuits.
NOTE: If this alarm occurs, Pretrip Test #2 will not be performed. Pretrip will need to be
restarted to continue testing.

UNIT CONTROL: Pretrip will fail and display "PRETRIP FAIL AND COMPLETED".

RESET CONDITION: Auto Reset if Pretrip is started again, or alarm may be manually reset via key-
pad or by turning the unit off, then back on again.
NOTE: Follow the steps below until a problem is found. Once a repair or correction has been made, clear the
alarm(s). (See Note 1 Page 7-1) Operate the unit through the appropriate modes to see if any active alarm oc-
curs. Continue with the steps below as necessary.
1 Check No Load Current Draw
a. Energize circuit (refer to Note 2
Page 7-2). Observe current draw
on microprocessor display.
b. Disconnect F5 wire and remove
from inside current sensing loop.
Reconnect at F5 and place SROS
in the ON position.
2 Check Individual Circuits
a. Isolate individual circuits and test
amp draw.
3 Check for parasitic loads.
a. Check for electrical loads that are
drawing current with all circuits
OFF
62-61753-21
ALARM / CAUSE CORRECTIVE ACTION
Reading is less than 1.5 Amps.
Without wire in loop, reading should be 0 +/- 1 amp.
Must be in range. (Refer to Section 2.12.)
Check for non-factory installed devices such as lift
gates, inside lights, satellite systems, etc. These de-
vices must be wired so as to not draw current during
pretrip testing.
7-72