Ford 2003 Mustang Workshop Manual page 3277

A4 CHECK GROUND CIRCUIT 397 (BK/WH) FOR AN OPEN
Key in OFF position.
Measure the resistance between the instrument cluster C220b pin
20, circuit 397 (BK/WH), harness side and ground.
Is the resistance less than 5 ohms?
A5 CHECK GROUND CIRCUIT 1205 (BK) FOR OPEN
Measure the resistance between the instrument cluster C220b pin 1,
circuit 1205 (BK), harness side and ground.
Is the resistance less than 5 ohms?
PINPOINT TEST B: INCORRECT FUEL GAUGE INDICATION
B1 CARRY OUT THE INSTRUMENT CLUSTER FUEL GAUGE
ACTIVE COMMAND
CAUTION: Use the correct probe adapter(s) when
making measurements. Failure to use the correct probe
adapter(s) may damage the connector. NOTE: Fuel fills of less
than 9.5 liters (2.5 gallons) require at least 10 minutes to update
the fuel gauge indication.
Key in ON position.
Select the instrument cluster FUELLEVEL active command.
Trigger, monitor, and scroll FUELLEVEL at: 0% , 50%, and
100%.
Does the fuel gauge display: below E at 0%, half at 50%, and
F at 100%?
B2 CHECK THE FUEL GAUGE OPERATION
Key in OFF position.
Disconnect: Fuel Pump Assembly C463.
Connect one lead of the Instrument Gauge System Tester to the
fuel pump module C463 pin 5, circuit 29 (YE/WH), harness side
and the other lead of the Instrument Gauge System Tester to the
Test Step
Yes
GO to A5 .
No
REPAIR the circuit.
TEST the system
for normal
operation.
Yes
REFER to Section
418-00 .
No
REPAIR the circuit.
TEST the system
for normal
operation.
Result / Action to
Take
Yes
GO to B2 .
No
GO to B8 .
Yes
GO to B3 .
No
GO to B5 .