Isuzu 4HL1 Workshop Manual page 210

1A-208 Engine Control System
Step
Check the idle position switch circuit (switch to
switch connector) for short.
1. Disconnect
connector.
7
2. Measure the resistance between the idle
position switch connector pins while
operating the switch with a finger.
Was the resistance within range?
Check the idle position switch circuit (ECM to
switch connector) for short.
1. Disconnect the vehicle side connector
from ECM.
8
2. Jumper the idle position switch connector
pin and measure the resistance at the
ECM connector.
Was the resistance within range?
Repair or replace the faulty harness.
9
Is the action complete?
Review the DTC.
1. Certainly connect the idle position switch
and ECM connectors.
10
2. Using Tech 2, clear the DTC.
3. Perform test run and review the DTC.
Is DTC242 detected?
1. Replace the ECM.
IMPORTANT:
If necessary (for the vehicle equipped with
11
idle stop function), input the number of
startups to the replacing ECM.
Is the action complete?
Check DTC242 will not be set again.
1. Using Tech 2, clear the DTC.
12
2. Perform test run and review the DTC.
Is DTC242 detected?
Action
the idle position switch
Value(s)
Switch-on
(switch is
released):
50 Ω, max.
Switch-off
(switch is
pressed): ∞ Ω
Go to Step 8
Pins 110-87
(jumpered):
0 Ω
(not jumpered):
∞ Ω
Go to Step 10
—
Go to Step 12
—
Go to Step 11
—
Verify repair and
go to Step 12
—
Diagnostic Aids
and go to Step 2
Yes
Go to Step 9
Go to Step 9
Refer to
Diagnostic Aids
Refer to
Repair is
complete
No
—
—