Isuzu 2000 Trooper Workshop Manual page 1225

6E–356
TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
ETC passage and on the ETC position, and excessive
deposits in the throttle bore and on the throttle plate.
D Large vacuum leak – Check for a condition that causes
a large vacuum leak, such as an incorrectly installed or
faulty PCV valve or brake booster hose disconnected.
DTC P0506 – Idle Air Control System Low RPM
Step
1 Was the "On-Board (OBD) System Check" performed?
2 Visually/physically inspect for the following conditions:
D
Throttle body tampering.
D
Restricted intake throttle system. Check for a
possible collapsed air intake duct, restricted air
filter element, or foreign objects blocking the air
intake system.
D
Throttle body: Check for objects blocking the
throttle
deposits in
throttle valve, and
throttle bore and on the throttle plate.
D
Throttle body with lever: Check for objects send
round the throttle spring lever that lever is smooth
movement, and spring lever has not excessive
play
Do any of the above require a repair?
3 Visually/physically inspect for the following conditions:
D
Acceleration pedal tampering.
D
Acceleration pedaL : Check for objects blocking
the spring or pedal arm.
D
Acceleration pedal : Check for objects move the
acceleration
movement, and acceleration pedal arm has not
excessive play.
Do any of the above require a repair?
4 1. Check for a poor connection at the throttle body
harness connector.
2. Check for a poor connection at the acceleration
position sensor harness connector.
3. If a problem is found, replace faulty terminals as
necessary.
Was a problem found?
5 Check the following circuits for an open, short
tovoltage, short to ground, or poor connection at
thePCM:
D
Throttle position sensor 1 circuit.
D
Throttle position sensor 2 circuit.
D
Throttle DC motor circuit.
D
Throttle position sensor resistance.
D
Throttle DC motor resistance.
D
If a problem is found, repair as necessary.
Was a problem found?
Action
passage or throttle bore, excessive
the throttle passage and on the
excessive deposits in the
pedal that pedal
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.
Value(s)
—
—
is smooth
—
—
Vcc-GND
1–7km
SIG-DND
change
resistance0.3
– 100m
Yes No
Go to OBD
System
Go to Step 2 Check
Refer
to appropriate
section
foron–vehicle
service
Go to Step 4
Refer
to appropriate
section
foron–vehicle
service
Go to Step 4
Verify repair Go to Step 7
Verify repair Go to Step 6