Ford F-150 1999 Workshop Manual page 12

1999 F-150/250 Workshop Manual
C2 CHECK THE PID WAC WITH THE A/C OFF
PCM PID WAC
C3 CHECK THE PID ACCS WITH THE A/C ON
NOTE: The outside temperature must be over 10° C (50° F).
PCM PID ACCS
C4 CHECK THE PID WAC WITH THE A/C ON
NOTE: The outside temperature must be over 10° C (50° F).
PCM PID WAC
C5 CHECK THE A/C CYCLING SWITCH VOLTAGE
A/C Cycling Switch C139
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Does the PCM PID ACCS read ON?
Yes
REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.
No
GO to C2.
Does the PCM PID WAC read ON?
Yes
REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.
No
GO to C3.
Place the function selector switch in the MAX A/C position.
Does the PCM PID ACCS read ON?
Yes
GO to C4.
No
GO to C5.
Does the PCM PID WAC read ON?
Yes
GO to C13.
No
REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.
Measure the voltage between the A/C cycling switch C139 pin 1, circuit 441 (RD/YE) and ground.
Is the voltage greater than 10 volts?
Page 12 of 30
8/16/2010