Isuzu 2008MY N Series Workshop Manual page 333

1A-330 Engine Control System (4HK1)
Step
1. Reenter the exhaust brake control.
2. Apply the clutch pedal while in exhaust brake
6
control.
Does the exhaust brake control cancel?
1. Park the vehicle.
2. Install a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Turn ON the ignition, with the engine OFF.
7 5. Monitor the DTC Information with a scan tool.
Are any DTCs set in which the "Action Taken
When the DTC Sets" under that particular
code states, "The ECM inhibits exhaust brake
control"?
1. Reenter the exhaust brake control.
2. Trigger the Snapshot function in order to
capture and store engine parameters while in
exhaust brake control.
3. Review the Exhaust Brake Valve Command
8
parameter.
Does the Exhaust Brake Valve Command
parameter indicate ON when the exhaust
brake may operate enough?
1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. Observe the Clutch Pedal Switch parameter
with a scan tool while fully depressing and
9
releasing the clutch pedal.
Does the scan tool indicate Applied when the
clutch pedal is applied and Released when
the clutch pedal is released?
1. Check to ensure the clutch pedal switch is
adjusted correctly. The plunger should be all
the way in when the pedal is released, yet
should not impede with the clutch pedal full
10
upward travel.
2. Adjust the clutch switch as necessary.
Did you find and correct the condition?
1. Turn OFF the ignition.
2. Disconnect the clutch pedal switch harness
connector.
3. Turn ON the ignition, with the engine OFF.
11
4. Connect a test lamp between the ignition
voltage feed circuit of the harness (pin 1 of B-
161) and a known good ground.
Does the test lamp illuminate?
Action Value(s) Yes
—
System OK
—
Go to Applicable
DTC
—
Go to Step 18
—
Go to Step 18
—
Go to Step 29
—
Go to Step 12
No
Go to Step 9
Go to Step 8
The ECM is not
allowing exhaust
brake control. Refer
to Exhaust Brake
Control Operation
Go to Step 10
Go to Step 11
Go to Step 13