Ford 2003 Mustang Workshop Manual page 3326

Measure the resistance between GEM C201e pin 22, circuit
1002 (BK/PK), harness side and CJB Fuse 32 (15A), pin 2,
circuit 1002 (BK/PK), harness side.
Is the resistance less than 5 ohms?
B8 CHECK GEM INPUT CIRCUIT FOR OPEN — KEY-IN-
IGNITION SWITCH CIRCUIT 158 (BK/PK)
Measure the resistance between GEM C201e pin 9, circuit
158 (BK/PK), harness side and ground.
Is the resistance less than 5 ohms?
B9 CHECK GEM VOLTAGE INPUT CIRCUITS FOR SHORT TO
POWER — IGNITION SWITCH CIRCUITS 911 (WH/LG), AND 1002
(BK/PK)
Key in OFF position.
Disconnect: CJB Fuse 28 (15A).
Disconnect: CJB Fuse 32 (15A).
Disconnect: GEM C201e.
Remove the ignition key. Measure the voltage between GEM
C201e pin 8, circuit 911 (WH/LG), harness side and ground,
and between GEM C201e pin 22, circuit 1002 (BK/PK),
harness side and ground.
Are the voltages greater than 10 volts?
B10 CHECK GEM INPUT CIRCUIT FOR SHORT TO GROUND —-
KEY-IN-IGNITION SWITCH CIRCUIT 158 (BK/PK)
Disconnect: GEM C201e.
Remove the ignition key. Measure the resistance between
GEM C201e pin 9, circuit 158 (BK/PK), harness side and
Yes
GO to B8 .
No
REPAIR the circuit.
REPEAT the self-test.
CLEAR the DTCs.
Yes
GO to B9 .
No
REPAIR circuit 158
(BK/PK) and key-in-
ignition switch for failure.
REFER to Switch—Key-
In-Ignition Warning .
REPEAT the self-test.
CLEAR the DTCs.
Yes
REPAIR the circuit in
question. REPEAT the
self-test. CLEAR the
DTCs.
No
GO to B10 .
Yes
GO to B11 .