Honda 2004 Odyssey Service Manual page 560

DTC P1491 '01 Model:
Insufficient Lift
1. Reset the PCM (see page 11-4).
2. Start the engine. Hold the engine at 3,000 rpm with
no load (in Park or neutral) until the radiator fan
comes on.
3. Test-drive the vehicle under load for about 10
minutes. Try to keep the engine speed in the
1,700 2,500 rpm range.
4. Check for a Temporary DTC with the scan tool or
the HDS.
Is T emporary DT C P1491 indicated?
YES Go to step 5.
NO Intermittent failure, system is OK at this time.
Check for poor connections or loose terminals at
the EGR valve and at the PCM.
5. Turn the ignition switch OFF.
6. Disconnect the EGR valve 6P connector.
7. Start the engine, and let it idle.
8. Measure voltage between EGR valve 6P connector
terminals No. 4 and No. 6.
EGR VALVE 6P CONNECTOR
EGR (PNK)
Wire side of female terminals
Is there battery voltage?
YES Substitute a known-good PCM, and recheck
(see page 11-5). If the symptom/indication goes
away, replace the original PCM.
NO Go to step 9.
EGR Valve
GND (BLK)
9. Turn the ignition switch OFF.
10. Turn the ignition switch ON (II).
11. Measure voltage between EGR valve 6P connector
terminals No. 2 and No. 3.
EGR VALVE 6P CONNECTOR
SG2
(GRN/BLK)
Wire side of female terminals
Is there about 5 V ?
YES Go to step 13.
NO Go to step 12.
12. Measure voltage between PCM connector
terminals A28 and A30.
PCM CONNECTOR A (31P)
SG2
(GRN/BLK)
Wire side of female terminals
Is there about 5 V ?
YES Repair open in the wire between the EGR
valve and the PCM (A28, A30).
NO Substitute a known-good PCM and recheck
(see page 11-5). If the symptom/indication goes
away, replace the original PCM.
VCC2
(YEL/BLU)
VCC2
(YEL/BLU)
(cont'd)
11-251