Dtc P0451: Ftp Sensor Range/Performance Problem - Honda S2000 Service Manual

DTC Troubleshooting
DTC P0451: FTP Sensor Ra nge/Perfo rmance
Problem
Special Tools Required
Vacuum Pump/Gauge,0 30 in. Hg A973X-041-XXXXX
1 . R e m o v e t h e f u e l f i l l c a p .
2. Turn the ignition switch ON(ll).
3. Monitor FTP sensor voltage with the Honda PG lvl
Tester, or measure voltage between ECM
c o n n e c t o r t e r m i n a l s A 2 9 a n d C 1 8 .
SG2 {GRN/YELI
Wire side of female terminals
ls there about 2.5 V?
YES- Go to step 4.
NO Replace the FTP sensor.I
4. Turn the ignition switch OFF.
PTANK {LT GRN)
5. Disconnect the hose between the EVAP two way
valve and the FTP sensor at the EVAP two way
valve end.
Ait973X-041-
6. Connect a vacuum pump to the open end of the
hose.
7 . T u r n t h e i g n i t i o n s w i t c h O N ( l l ) .
8. Monitor FTP sensor voltage with the Honda PGM
Tester, or measure voltage between ECM
connector term ina ls A29 and C18, and very slowly
to squeeze the vacuum pump.
L The voltage should smoothly drop from about 2.5 V
down to about 1.5 V. Stop applying vacuum when
the voltage drops to about 1.5 V or damage to the
FTP sensor may occur.
Does the voltage drcp to about 1.5 V and hold?
YES lntermittent failure, system is OK at this time.
Check for poor connections at the FTP sensor and
t h e E c M . I
NO - Replace the FTP sensor.l
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