Isuzu 2008MY N Series Workshop Manual page 334

Step
Observe the Clutch Pedal Switch parameter with a
scan tool while momentarily jumping 3-amp fused
jumper wire across the switch harness connector
between pins 1 and 2 of the B-161.
12
Does the scan tool indicate Released when
the circuit is jumpered and Applied when the
circuit is not jumpered?
Repair the open circuit or high resistance between
the ECM (10A) fuse and the switch (pin 1 of B-161).
13
Did you complete the repair?
1. Test the signal circuit between the ECM (pin
26 of J-14) and the switch (pin 2 of B-161) for
the following conditions:
• An open circuit
14
• A short to battery or ignition voltage
• High resistance
2. Repair the circuit(s) as necessary.
Did you find and correct the condition?
1. Inspect for an intermittent and for poor
connections at the harness connector of the
switch (pins 1 and 2 of B-161).
15
2. Repair the connection(s) as necessary.
Did you find and correct the condition?
1. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for a poor
connection at the harness connector of the
16
ECM (pin 26 of J-14).
4. Repair the connection(s) as necessary.
Did you find and correct the condition?
Replace clutch switch. Refer to Clutch Control in
Section 5E Clutch.
17
Did you complete the replacement?
1. Perform the Exhaust Brake Control with a
scan tool.
2. Command the solenoid ON and OFF.
Does the solenoid valve click with each
18
command?
1. Turn OFF the ignition.
2. Disconnect the exhaust brake solenoid valve
harness connector.
3. Turn ON the ignition, with the engine OFF.
19
4. Connect a test lamp between the ignition
voltage feed circuit (pin 1 of J-26) and a
known good ground.
Does the test lamp illuminate?
Action
Engine Control System (4HK1)
Value(s) Yes
—
Go to Step 15
—
Go to Step 29
—
Go to Step 29
—
Go to Step 29
—
Go to Step 29
—
Go to Step 29
Problem is relating
to solenoid valve,
exhaust brake valve
or vacuum pressure
—
lines. Refer to
applicable
diagnostic chart in
Section 1G Engine
Exhaust.
—
Go to Step 20
1A-331
No
Go to Step 14
—
Go to Step 16
Go to Step 17
Go to Step 28
—
Go to Step 19
Go to Step 22