Ford 2003 Mustang Workshop Manual page 2151

EVAP lines or hoses
Vacuum lines or hoses
3. If the concern remains after the inspection, connect the scan tool to the data link connector
(DLC) located beneath the instrument panel and select the vehicle to be tested from the scan
tool menu. If the scan tool does not communicate with the vehicle:
check that the program card is correctly installed.
check the connections to the vehicle.
check the ignition switch position.
4. If the scan tool still does not communicate with the vehicle, refer to the scan tool manual.
5. Carry out the DATA LINK DIAGNOSTICS test. If the scan tool responds with:
CKT914, CKT915 or CKT70 = ALL ECUS NO RESP/NOT EQUIP, refer to
NO RESP/NOT EQUIP for PCM, refer to the Powertrain Control/Emissions Diagnosis (PC/ED)
manual.
SYSTEM PASSED, retrieve and record the continuous diagnostic trouble codes (DTCs), erase
the continuous DTCs and carry out the PCM KOEO self-test.
6. If the DTCs retrieved are related to the concern, go to the PCM Diagnostic Trouble Code (DTC)
Index to continue diagnostics.
7. If the concern remains after the inspection, determine the symptom. GO to
PCM Diagnostics Trouble Code (DTC) Index
DTC Description
P0442 Small leak detected in EVAP system
(As small as 1.02 mm [0.040 inch])
P0455 Major leak or no flow detected
P0457 Check for missing or leaking fuel filter
cap
P1443 Very small or no purge flow detected
P1450 Excessive vacuum detected in the fuel
tank
— Any other PCM DTC
Symptom Chart
SYMPTOM CHART
Condition
Hissing sound when
removing fuel cap
Source
PCM Go To Pinpoint Test A
PCM Go To Pinpoint Test B
PCM Go To Pinpoint Test A
PCM Go To Pinpoint Test B
PCM Go To Pinpoint Test C
PCM REFER to the Powertrain
Control/Emissions Diagnosis (PC/ED)
manual.
Possible Sources
Canister vent solenoid.
Evaporative emissions
canister.
Fuel vapor control valve
Section 418-00 .
Symptom Chart .
Action
.
.
.
.
.
Action
Go To Pinpoint
Test D .