Ford 2003 Mustang Workshop Manual page 3056

high speed
No operation in high
blower setting
No operation in lower
speeds
Pinpoint Tests
PINPOINT TEST P1464: DTC P1464: A/C DEMAND OUT OF SELF-
TEST RANGE
P14641 RECHECK FOR THE DTC
Key in ON position.
Make sure the function selector switch is in the OFF
position.
Enter the following diagnostic mode on the diagnostic
tool: PCM Self-Test.
Is DTC P1464 retrieved?
P14642 CHECK PID ACCS WITH THE A/C CONTROL
DISCONNECTED
Key in OFF position.
Disconnect: Function Selector Switch C294c.
Key in ON position.
Enter the following diagnostic mode on the diagnostic
tool: PCM PID ACCS.
Does PID ACCS read ON?
P14643 CHECK CIRCUIT 348 (VT) FOR A SHORT TO B+
Key in OFF position.
Disconnect: PCM C175.
Key in ON position.
Measure the voltage at the function selector switch
C294c-4, circuit 348 (VT), the harness side and ground.
motor switch resistor.
Damaged heater blower
motor switch.
Circuitry short/open.
Damaged heater blower
motor switch.
Circuitry short/open.
Damaged heater blower
motor switch resistor.
Damaged heater blower
motor switch.
Test Step
Test H .
Go To
Pinpoint
Test I .
Go To
Pinpoint
Test J .
Result / Action to Take
Yes
GO to P14642 .
No
The system is functioning
correctly. This DTC will set if the
A/C is turned on when carrying
out the PCM self-test.
Yes
GO to P14643 .
No
INSTALL a new function selector
switch. REFER to Section 412-
04 . REPEAT the PCM self-test
and verify DTC P1464 is no
longer retrieved.
Yes
REPAIR circuit 348 (VT ) for a
short to B+. REPEAT the PCM
self-test and verify DTC P1464 is
no longer retrieved.
No
INSTALL a new powertrain
control module. REFER to
Section 303-14 . REPEAT the
PCM self-test and verify DTC
P1464 is no longer retrieved.