Isuzu N 2008 Series Workshop Manual page 325

1A-322 Engine Control System (4JJ1)
• The MIL/ SVS lamp circuit intermittently shorted to
ground
• Electrical system interference caused by a
malfunctioning relay, ECM driven solenoid, or
switch. The electrical component can cause a
sharp electrical surge. Normally, the problem will
occur when the malfunctioning component is
operating.
• There are any open diodes.
Important: The following symptom tables contain
groups of possible causes for each symptom. The
order of these procedures is not important. If the scan
tool readings do not indicate the problems, then
proceed in a logical order, easiest to check or most
likely to cause first. In order to determine if a specific
vehicle is using a particular system or component, refer
to engine control wirings for an application.
Use the following tables when diagnosing a symptom
complaint:
• Intermittent Conditions
• Hard Start
• Rough, Unstable, or Incorrect Idle and Stalling
• High Idle Speed
• Cuts Out
• Surges
• Lack of Power, Sluggishness or Sponginess
• Hesitation, Sag or Stumble
• Abnormal Combustion Noise
• Poor Fuel Economy
• Excessive Smoke (Black Smoke)
• Excessive Smoke (White Smoke)
• DPD System Manual Regeneration Frequently
• DPD System Regeneration Long Time