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Isolation Test

NOTE: For wire color and connector terminal identification, see CRUISE CONTROL CONNECTOR IDENTIFICATION  table.
  1. Disconnect cruise control module connector. Use a DVOM. Ensure ignition switch is in ON position when checking voltage and in OFF position when checking resistance.
  2. Turn cruise control switch off, and set DVOM on 200-ohm scale. Check resistance between terminal "J" and ground. Resistance should be zero ohms. If resistance is not zero ohms, check Black ground wire for an open circuit.
  3. Turn ignition on. With DVOM on 20-volt scale, check voltage between terminals "A" and "J", and terminals "M" and "J". Voltage should be zero volts. If voltage is other than zero volts, go to CRUISE SWITCH SHORT TEST . Turn ignition off.
  4. With cruise control switch on, set DVOM on 200-ohm scale. Check resistance between terminals "C" and "J". Resistance should be 30-55 ohms. If resistance is less than 30 ohms, refer to VENT CIRCUIT SHORT TEST . If resistance is greater than 55 ohms, refer to, in this article, VENT CIRCUIT OPEN TEST .
  5. With DVOM on 200-ohm scale, check resistance between terminals "K" and "J". Resistance should be 30-55 ohms. If resistance is less than 30 ohms, go to VAC CIRCUIT SHORT TEST . If resistance is greater than 55 ohms, go to VAC CIRCUIT OPEN TEST .
  6. With DVOM on 200-ohm scale, check resistance between terminals "F" and "H". Resistance should be 15-25 ohms. If resistance is less than 35 ohms, go to VAC CIRCUIT SHORT TEST . If resistance is greater than 35 ohms, go to SPS CIRCUIT OPEN TEST .
  7. Turn ignition on. With DVOM on 20-volt scale, check voltage between terminals "A" and "J". Battery voltage should be present. If battery voltage is not present, go to POWER CIRCUIT OPEN TEST .
  8. With DVOM on 20-volt scale, check voltage between terminals "G" and "J". Battery voltage should be present. If battery voltage is not present, go to BRAKE CIRCUIT OPEN TEST .
  9. With DVOM on 20-volt scale, check voltage between terminals "M" and "J" and terminals "L" and "J". Voltage should be zero volts in both tests. If voltage is other than zero volts, go to CRUISE SWITCH SHORT TEST .
  10. Turn cruise switch on. Press and hold SET button. With DVOM on 20-volt scale, check voltage between terminals "L" and "J". Battery voltage should be present. If battery voltage is not present, go to SC CIRCUIT OPEN TEST .
  11. Place cruise switch in R/A position. With DVOM on 20-volt scale, check voltage between terminals "M" and "J". Battery voltage should be present. If battery voltage is not present, go to R/A CIRCUIT OPEN TEST .
  12. Turn cruise switch on and turn drive wheels by hand. With DVOM on 20-volt scale, check voltage between terminals "A" and "D". Voltage should fluctuate between battery voltage and less than 7 volts. If voltage is not correct, refer to VSS CIRCUIT OPEN TEST  and VSS CIRCUIT SHORT TEST . Turn ignition off.
  13. With DVOM on 200-ohm scale, check resistance between terminals "F" and "J". Resistance should read infinity (open circuit). If reading is not correct, go to R/A CIRCUIT SHORT TEST .
  14. Check resistance between terminals "F" and "C", terminals "F" and "K", terminals "H" and "C", and terminals "H" and "K". Resistance should read infinity (open circuit) in each test. If readings are not correct, go to SERVO RESISTANCE TEST .
  15. If all ISOLATION TEST  measurements are correct, go to SERVO ACTUATION TEST .
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