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Category: Heavy Equipment
Satisfied Customers: 3677
Experience:  16 Years working on Cummins Diesel engines,
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2005 volvo: quit working..idling..One can be disconnected

Customer Question

we have 2005 volvo vnl670 big rig. It has icon (optimized idle) on it which has quit working so truck will not stay idling to run heat or air. One mechanic tells me it can be disconnected and not cause any problems, another tells me no. It has cummins 465-550 motor. can you please advise me? you can call house at XXXXXXXXXX I appreciate any information you can give me.
Lucius Stevenson XXXXX
Orangeburg, sc
Submitted: 6 years ago.
Category: Heavy Equipment
Expert:  DR.Cummins replied 6 years ago.
Hello and welcome to Just Answer! I would be more than happy to assist you today.can i have your engine serial number?
Expert:  DR.Cummins replied 6 years ago.

To activate the ICONTM system, perform the following steps:

  • Idle the engine. Do not turn on the PTO. Do not touch the accelerator pedal
  • Set the parking brake.

Once the I

  • Turn the cruise control switch from the OFF position to the ON position.

NOTE: If the switch is already on, you must turn it off then back on. At this point, the ICONTM lamp will start flashing quickly. This lamp flashing pattern confirms that the ICONTM system is ready to be activated.

The following step must be completed within 1 minute of turning on the cruise control switch, or the ICONTM system will be deactivated automatically.

  • The ICONTM system will verify that the vehicle is in neutral. While continuously holding the clutch pedal in, shift the transmission into gear. The ICONTM lamp will flash at a slow rate (approximately 2-Hz per second). Then, shift the transmission back into neutral, and release the clutch pedal. The ICONTM lamp will light and pulse at a rate of approximately 1-Hz per second.

The ICONTM system is now active and will default to engine mode.

CONTM system has been activated, the default mode is the engine mode. When the operator turns on and sets the cab thermostat, the ICONTM system enters cab comfort mode. The cab comfort mode will shut off and restart the engine as required to keep the batteries charged, engine oil temperature above the minimum specification, and maintain the cab temperature at the desired set level. The following steps will occur automatically while the ICONTM system is in cab comfort mode:

  • When the ICONTM system is activated, the engine rpm will slowly ramp up to the ICONTM idle speed. The ICONTM system can initially ramp the engine up to a higher rpm (ICONTM maximum rpm) to supply a higher alternator output then lower the idle speed back down to the ICONTM idle speed.
  • The engine will run for a minimum specified time to reach the engine oil temperature and cab comfort temperature. The engine will run for a minimum amount of time if the battery voltage is low. If the battery charge and the engine oil temperature is above the maximum specification, and the cab temperature is within the set temperature parameters, the ICONTM system will slowly ramp down the idle speed to the minimum idle speed or the ICONTM idle speed (whichever is higher). When the lower engine speed is reached, the ICONTM system will shut down the engine after the initial minimum run time. If the battery is not charged, the engine oil is too cold, or the cab temperature is not within the set temperature parameters, the engine will continue to run until these thresholds are met. When the engine is off, the ignition power will also be turned off.
  • When the engine is not running, the ICONTM system remains in a wait period. During the wait period, the ICONTM lamp will remain on, pulsing at a slow rate. The ICONTM system continuously monitors the status of the cab temperature, the engine oil temperature, and the battery voltage level. If cab temperature, engine oil temperature, or battery voltage level drops below the minimum specification, the ICONTM system will restart the engine.
  • After engine restart, step 1 and step 2 will repeat with one exception; the ignition power to the accessories will remain off for the first 20 seconds after the engine has started and is running at the ICONTM idle speed.

The preferred method of deactivating the ICONTM system is to turn off the cruise control switch. To restart the engine, after deactivating the ICONTM system, cycle the keyswitch from ON to OFF, then manually restart the engine.

After the ICONTM system has been activated in either engine mode (including keyless engine mode) or cab comfort mode, the ICONTM system will be deactivated if any of the following occurs:

  1. Interlock switch open (neutral, parking, hood)
  2. Vehicle speed greater than 0 mph
  3. A Fault becomes active in the ICONTM system
  4. (Aftermarket systems only) accelerator is depressed with keyswitch on or off (keyless engine mode) before first shutdown
  5. Cruise control switch turned off
  6. Keyswitch turned off after first shutdown
  7. (Aftermarket or OEM systems only) keyswitch turned on when in keyless engine mode
  8. (Aftermarket systems only) PTO is activated with keyswitch on or off (keyless engine mode) before first shutdown


Expert:  DR.Cummins replied 6 years ago.
it can also be disabled thru the ecm features and parameters by Cummins or a dealer.And can only be done Via Cummins insite program. But this will disable the entire ICON system.