Briggs & Stratton VANGUARD M490000, Repair Manual

Page: 69 / 144

2
65
DTC P0505 Idle Air Control (IAC) Malfunction (Non-Scan Diagnostics)
Step Action Yes No
1 1. Disconnect and reconnect IAC and TPS connectors.
2. Turn Ignition ON, Engine OFF.
3. Clear codes.
4. Turn Ignition OFF, and then back ON.
5. Does DTC return?
Go to step 2. Problem corrected.
2 1. Start engine and allow it to warm up for 5 minutes.
2. When engine idle speed is stabilized, use tachometer to record RPM.
3. Is tachometer reading 750-950 RPM?
NOTE: Cold engine temperatures and low battery voltages can cause high engine
idle speeds. For example, at -18° F (-28° C), idle speed can be as high as 1350
RPM, while low battery voltages at normal engine operating temperatures can
cause the engine idle speed to reach 1200 RPM.
Look for
intermittent
conditions.
Go to step 3.
3 1. Turn Ignition OFF.
2. Back probe terminal 3 (Pink/Black wire) of TPS connector.
3. Connect terminal 3 back probe to red meter test lead on DVOM.
4. Connect black meter test lead on DVOM to a known good ground.
5. Set DVOM to read volts DC.
6. Start engine and run at idle speed.
7. Does DVOM read 0.5-0.75 volts DC?
Go to step 4. Reset TPS.
See TPS Removal/Installation/
Adjustment in SECTION 5 -
REMOVAL/INSTALLATION.
4 1. Turn Ignition OFF.
2. Remove IAC from throttle body and inspect for stuck pintel or carbon build up in
IAC port.
3. Are either of these conditions found?
Clean or repair
as necessary.
Return to step
2 and repeat
test procedure.
Inspect for intake tract leaks
after the throttle body.
TPS Connector
Not for
Reproduction