Idle Air Volume Learning
“Idle Air Volume Learning” is an operation to learn the idle air volume
that keeps each engine within the specific range. It must be
performed under any of the following conditions:
-Each time IACV-AAC valve, throttle body or ECM is replaced.
-Idle speed or ignition timing is out of specification.
Before performing “Idle Air Volume Learning”, make sure that all of
the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are
missed for even a moment.
- Battery voltage: More than 12.9V (At idle)
- Engine coolant temperature: 70 - 95?C (158 - 203?F)
- PNP switch: ON
- Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, if the parking
brake is applied before the engine is started the headlamp
will not be illuminated.
- Cooling fan motor: Not operating
- Steering wheel: Neutral (Straight-ahead position)
- Vehicle speed: Stopped
- Transmission: Warmed-up
For A/T models with CONSULT-II, drive vehicle until “FLUID
TEMP SE” in “DATA MONITOR” mode of “A/T” system indicates
less than 0.9V.
For A/T models without CONSULT-II and M/T models, drive
vehicle for 10 minutes.
1. Turn ignition switch “ON” and wait at least 1 second.
2. Turn ignition switch “OFF” and wait at least 10 seconds.
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic “PRECONDITIONING”,
EC-83, are in good order.
5. Turn ignition switch “OFF” and wait at least 10 seconds.
6. Start the engine and let it idle for at least 30 seconds.
7. Disconnect throttle position sensor harness connector (<wbr>brown),
then reconnect it within 5 seconds.
8. Wait 20 seconds.
9. Make sure that idle speed is within specifications. If not, the
result will be incomplete. In this case, find the cause of the
problem by referring to the NOTE below.
10. Rev up the engine two or three times. Make sure that idle
speed and ignition timing are within specifications.
If idle air volume learning cannot be performed successfully,
proceed as follows:
1) Check that throttle valve is fully closed.
2) Check PCV valve operation.
3) Check that downstream of throttle valve is free from air
4) Adjust closed throttle position <wbr>switch and reset memory.
(Refer to Basic Inspection, EC-127.)
5) When the above three items check out OK, engine component
parts and their installation condition are questionable.
Check and eliminate the cause of the problem.
It is useful to perform “TROUBLE DIAGNOSIS SPECIFICATION
6) If any of the following conditions occur after the engine
has started, eliminate the cause of the problem and perform
“Idle air volume learning” all over again:
- Engine stalls.
- Erroneous idle.
- Blown fuses related to the IACV-AAC valve system.