Isuzu N 2008 Series Workshop Manual page 313

1A-310 Engine Control System (4JJ1)
Step
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.
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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
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
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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
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upward travel.
2. Adjust the clutch pedal 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.
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4. Connect a test lamp between the ignition
voltage feed circuit (pin 1 of B161) and a
known good ground.
Does the test lamp illuminate?
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 B161.
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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 B161).
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Did you complete the repair?
Action
Brake Valve Command
Value(s) Yes
—
Go to Applicable
DTC
—
Go to Step 18
—
Go to Step 18
—
Go to Step 29
—
Go to Step 12
—
Go to Step 15
—
Go to Step 29
No
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
Go to Step 14
—