Ftp Sensorrange/Performance Problem - Honda Civic 2002-2003 Service Manual

• OTe Troubleshooting
•
•
OTe P0451:
FTPSensorRange/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 fuel tank pressure (FTP) sensor voltage
with the Honda PGM Tester, or
me~sure
voltage
between ECM connector terminals E4 and E14.
ECM CONNECTOR E 131 PI
SG31PNKI
1 213 4 5 6 7 I
18 9
'Y
1/1 1/1/1,11 415 16 1/118V120 21
22231241
l
~ 27VI29130 31
FTPILTGRNI
Wire side of female terminals
Is there about 2.SV?
YES-Go to step 4.
NO-Replace the FTPsensor .•
4. Turn the ignition switch OFF.
5. Disconnect the hose between the EVAP two way
valve and the FTPsensoralthe EVAP two way
valve end.
6. Connect a vacuum pump to the open end of the
hose.
7. Turn the ignition switch ON (II).
8. Monitor FTP sensor voltage with the Honda PGM
Tester, or measure voltage between ECM
connector terminals E4 and E14, and carefully
squeeze the vacuum pump a little.
ECM CONNECTOR E 131PI
SG31PNKI
1 213 4 5 6 7 I 18 9
'Y /
/1/1. '11 415 16 1/1181/120 21
22231241
L
~ 271/129130 31
FTPILTGRNI
Wire side of female terminals
9. The voltage should smoothly drop from about 2.5 V
to about 1.5 V. Stop applying vacuum when the
voltage drops to about 1.5 V or damage to the FTP
sensor may occu r.
Does the voltage drop 10 about 1.5 V and hold?
YES-Check for misrouted, leaking, or broken FTP
sensor vacuum lines. If the vacuum lines are OK,
update the ECM if it does not have the latest
software, or substitute a known-good ECM, then
recheck Isee page 11-6). If the symptom/indication
goes away with a known-good ECM, replace the
original ECM .•
NO- Replace the FTP sensor .•
11-171