2003 FORD MUSTANG Workshop Manual

Page 3273 of 4378

FORD MUSTANG 2003  Workshop Manual indication—
Cobra only  �zInstrument 
cluster. 
�z The LOW FUEL warning 
indicator is never/always 
on  �z
LOW FUEL 
warning 
indicator bulb. 
�z Standard 
corporate 
protocol (SCP) 
network. 
�z In

Page 3274 of 4378

FORD MUSTANG 2003  Workshop Manual �z
Powertrain 
control module 
(PCM).  manual. 
�z The CHECK FUEL CAP 
INDICATOR is never on  �z
Circuitry. 
�z Standard 
corporate 
protocol (SCP) 
network. 
�z Powertrain 
control module 
(PCM).  �z

Page 3275 of 4378

FORD MUSTANG 2003  Workshop Manual Pinpoint Tests 
PINPOINT TEST A: NO COMMUNICATION WITH THE INSTRUMENT 
CLUSTER  �z
The SERVICE ENGINE 
SOON indicator is 
never/always on  �z
Circuitry. 
�z SERVICE 
ENGINE 
SOON 
indicator bulb. 
�z

Page 3276 of 4378

FORD MUSTANG 2003  Workshop Manual A1 CHECK THE BATTERY POWER SUPPLY TO THE INSTRUMENT 
CLUSTER   CAUTION: Use the correct probe adapter(s) when making 
measurements. Failure to use the correct probe adapter(s) may 
damage the connecto

Page 3277 of 4378

FORD MUSTANG 2003  Workshop Manual PINPOINT TEST B: INCORRECT FUEL GAUGE INDICATION  A4 CHECK GROUND CIRCUIT 397 (BK/WH) FOR AN OPEN 
�z
Key in OFF position. 
�z Measure the resistance between the instrument cluster C220b pin 
20, circ

Page 3278 of 4378

FORD MUSTANG 2003  Workshop Manual fuel pump module C463 pin 8, circuit 327 (BK/OG), harness side. 
�z Set the Instrument Gauge System Tester to 160 ohms. 
�z Key in ON position. 
�z Turn the ignition switch to RUN for one second. 
�z

Page 3279 of 4378

FORD MUSTANG 2003  Workshop Manual �z
Is any voltage present?  B6 CHECK THE FUEL PUMP ASSEMBLY FEED CIRCUIT 29 
(YE/WH)  �z
Key in OFF position. 
�z Measure the resistances between the instrument cluster C220b 
pin 19, circuit 29 (YE/W

Page 3280 of 4378

FORD MUSTANG 2003  Workshop Manual PINPOINT TEST C: INCORRECT OIL PRESSURE GAUGE 
INDICATION  �z
Operate the system and verify the concern is still present. 
�z Is the concern still present?  normal operation. 
No 
The system is 
opera