Ford 2003 Mustang Workshop Manual page 3303

OPEN
Key in OFF position.
Measure the resistance between the GEM C201b pin 4,
circuit 397 (BK/WH), harness side and ground.
Is the resistance less than 5 ohms?
W3 CHECK CIRCUIT 397 (BK/WH) FOR SHORT TO POWER
Measure the voltage between the GEM C201b pin 4, circuit
397 (BK/WH), harness side and ground.
Is any voltage present?
Yes
GO to W3 .
No
REPAIR the circuit(s) in
question. TEST the system
for normal operation.
Yes
REPAIR the circuit. TEST
the system for normal
operation.
No
REFER to Section 418-00 .