Dtc Troubleshooting - Honda 2004 Odyssey Service Manual

DTC Troubleshooting

DTC P0505: Malfunction in Idle Control
System
NOTE: If DTC P1519 is stored at same time as DTC
P0505, troubleshoot DTC P1519 first, then recheck for
DTC P0505.
1. Start the engine. Hold the engine at 3,000 rpm with
no load (in Park or neutral) until the radiator fan
comes on.
2. Check the engine speed at idle with no-load
conditions: headlights, blower fan, rear window
defogger, radiator fan, and air conditioner are not
operating.
Is the engine running at 7 30 50 rpm?
YES Intermittent failure, system is OK at this
time.
NO If the idle speed is less than 680 rpm, go to
step 3; if it's 780 rpm or higher, go to step 4.
3. Disconnect the IAC valve 3P connector.
Does the engine speed increase or f luctuate?
YES Adjust the idle speed (see page 11-201). If the
idle speed will not adjust properly, clean the
passage in the throttle body, and then adjust it
again.
NO Replace the IAC valve.
4. Turn the ignition switch OFF.
5. Remove the intake air duct from the throttle body.
6. Start the engine, and let it idle.
7. Put your fingers on the lower port (A) in the throttle
body.
Does the engine speed drop?
YES Check the idle speed (see page 11-201). If it's
out of specification, replace the IAC valve.
NO Check for vacuum leaks with the throttle valve
completely closed, and repair as needed.
A
11-183