Idle Speed - Subaru 2004 Impreza Service Manual

3. Idle Speed

A: INSPECTION
1) Before checking idle speed, check the following:
(1) Ensure the air cleaner element is free from
clogging, ignition timing is correct, spark plugs
are in good condition, and the hoses are con-
nected properly.
(2) Ensure the malfunction indicator light does
not illuminate.
2) Warm up the engine.
3) Stop the engine, and then turn the ignition switch
to OFF.
4) When using the Subaru Select Monitor, refer to
the following. <Ref. to ME(H4SO)-16, SPECIAL
TOOLS, PREPARATION TOOL, General Descrip-
tion.>
(1) Insert the cartridge to Subaru Select Moni-
tor.
(2) Connect the Subaru Select Monitor to data
link connector.
(3) Turn the ignition switch to ON, and Subaru
Select Monitor switch to ON.
(4) Select the {2. Each System Check} in Main
Menu.
(5) Select the {Engine Control System} in Se-
lection Menu.
(6) Select the {1. Current Data Display & Save}
in Engine Control System Diagnosis.
(7) Select the {1.12 Data Display} in Data Dis-
play Menu.
(8) Start the engine, and then read the engine
idle speed.
5) When using the tachometer (Secondary pick-up
type).
(1) Attach the pick-up clip to No. 1 cylinder
spark plug cord.
Idle Speed
(2) Start the engine, and then read the engine
idle speed.
NOTE:
• When using the OBD-II general scan tool, care-
fully read its operation manual.
• This ignition system provides simultaneous igni-
tion for #1 and #2 plugs. It must be noted that some
tachometers may register twice that of actual en-
gine speed.
6) Check the idle speed when unloaded. (With
headlights, heater fan, rear defroster, radiator fan,
air conditioning, etc. OFF)
Idle speed [No load and gears in neutral (MT
model), or N or P (AT model) range]:
1.6 L and 2.0 L model:
2.5 L model:
ME-00325
7) Check the idle speed when loaded. (Turn the air
conditioning switch to "ON" and operate the com-
pressor for at least 1 minute before measurement.)
Idle speed [A/C "ON" and gears in neutral (MT
model) or N or P (AT model) range]:
850 ± ± ± ± 100 rpm
NOTE:
Idle speed can not be adjusted manually, because
the idle speed is automatically adjusted.
If the specified idle speed can not be maintained,
refer to General On-board Diagnosis Table under
"Engine Control System". <Ref. to EN(H4SO)(di-
ag)-2, Basic Diagnostic Procedure.>
ME(H4SO)-27
650 ± ± ± ± 100 rpm (With OBD)
700 ± ± ± ± 100 rpm (Without OBD)
650 ± ± ± ± 100 rpm
MECHANICAL
ME-00193