Honda 2004 Odyssey Service Manual page 571

EVAP System
DTC Troubleshooting (cont'd)
DTC P0451 '01 Model:
Performance Problem
Special Tools Required
Vacuum pump/gauge, 0 30 in.Hg A973X-041-XXXXX
1. Remove the fuel fill cap.
2. Turn the ignition switch ON (II).
3. Monitor the FTP sensor voltage with the HDS, or
measure voltage between PCM connector
terminals E7 and E28.
PCM CONNECTOR E (31P)
Wire side of female terminals
Is there about 2.5 V ?
YES Go to step 4.
NO Replace the FTP sensor.
4. Turn the ignition switch OFF.
5. Disconnect the hose between the EVAP two way
valve and the FTP sensor at the EVAP two way
valve end.
11-262
FTP Sensor Range/
SG3 (GRN/BLK)
FTP (LT GRN)
6. Connect a vacuum pump to the open end of the
hose.
A973X-041-XXXXX
7. Turn the ignition switch ON (II).
8. Monitor the FTP sensor voltage with the HDS, or
measure voltage between PCM connector
terminals E7 and E28, and slowly squeeze the
vacuum pump one stroke at a time.
9. The voltage should drop 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.
PCM CONNECTOR E (31P)
Wire side of female terminals
Does the voltage drop to about 1.5 V and hold?
YES Check for misrouted, leaking, or broken FTP
sensor vacuum lines. If the vacuum lines are OK,
substitute a known-good PCM and recheck (see
page 11-5). If the symptom/indication goes away,
replace the original PCM.
NO Replace the FTP sensor.
SG3 (GRN/BLK)
FTP (LT GRN)