Ion Sense Ignition For Model Year 2000 (IB00-S001)

ION SENSE IGNITION FOR MODEL YEAR 2000

TECHNICAL SERVICE BULLETIN

Affected Vehicles

All Model Year 2000 Trooper, Rodeo, and Amigo with the V-6 Engine.

Service Information

All Model Year 2000 Trooper, Rodeo, and Amigo with the V-6 engine have the new Ion Sense Ignition (ISI). This ignition system is capable of electrically biasing the spark plug gap after the plug has fired to facilitate the monitoring of a "Combustion Event". In essence the spark plug now has become an "in-cylinder" combustion sensor. The system enables the PCM to perform three separate functions:

1. Cylinder Identification
2. Individual Cylinder Knock Detection
3. Individual Cylinder Misfire Detection

The Ion Sense Ignition system has eliminated the need for Knock and Cam Sensors. It has also eliminated the Rough Road input needed in the past for misfire detection. However, the technician should be aware of some specific service issues that can and cannot be performed while performing diagnostics and testing.

The Technician can: 

• Disconnect the coils for diagnostics.
• Swap coils between cylinders 1-5 for diagnostics.
• Measure the resistance at the three pin connector on the coil for diagnostics.
• Disconnect the J-1 from the ISIM, turn the key to the on position, and crank the vehicle for diagnostics.

The Technician cannot: 

• Swap the coil from #6 cylinder with any other cylinder. (The coil for #6 cylinder is 3/16 of an inch shorter than the rest of the cylinders.)
• Start the engine with the ISIM unbolted from the engine. If the ISIM is not grounded, it will internally short.
• "Probe" the Sec A or Sec B lines. These lines have very high voltage.
• Crank/start the engine with connector J-2 or J-3 disconnected from the ISIM.
• Crank/start the engine without the coils bolted/grounded to the engine. The coils will become damaged.
• Remove the secondary spring from the secondary boot.
• Swap the ISIM's between the 3.2L and the 3.5L engines.
• Apply grease to the ISIM connectors nor clean the ISIM connectors with any type of cleaning solvent. The connectors must be kept clean and free of all contaminates.

Ion Sense Ignition Summary

Below are some of the values of the Ion Sense Ignition Coil and Boot Assembly:

Pin	Name	Description
A	B+	Primary Power
B	SEC	Ion Signal Side of Secondary
C	C-	Switched Primary

Pins	Resistance
A - C	~ 0.4 ohms
B - Boot Spring	~ 3,000 ohms
A - B or C - B	Open Circuit