U0104 Lost Communication With Cruise Control Module (CCM)
OBD2 Error Codes

U0104 Lost Communication With Cruise Control Module (CCM)

U0104 Lost Communication With Cruise Control Module (CCM)

OBD-II DTC Datasheet

Lost Communication With Cruise Control Module (CCM)

What does this mean?

This is a generic communications DTC that applies to most makes and models of vehicles, including but not limited to Chevrolet, Cadillac, Ford, GMC, Mazda, and Nissan. This code means that the cruise control module (CCM) and other control modules on the vehicle are not communicating with each other.

The circuitry most commonly used for communication is known as Controller Area Bus communication, or simply the CAN bus. Without this CAN bus, control modules cannot communicate and your scan tool may not receive information from the vehicle, depending on which circuit is involved.

Without this communication scheme, CCM does not know what the driver wants to choose. By default, it should go to a safe position; in other words, it will be off by default.

Troubleshooting steps may vary depending on the manufacturer, the type of communication system, the number of wires, and the colors of the wires in the communication system.

symptoms

Symptoms of a U0104 engine code may include:

  • Malfunction Indicator Light (MIL) is on
  • Cruise control does not turn on
  • If part of the steering column control unit, then the ABS / TRAC / ESC lights may also come on.

reasons

Usually the reason for installing this code is:

  • Open in CAN + bus circuit
  • Open in the CAN bus - electrical circuit
  • Short circuit to power in any CAN bus circuit
  • Short to ground in any CAN bus circuit
  • Rarely - the control module is faulty

Diagnostic and repair procedures

A good starting point is always to check the Technical Service Bulletins (TSB) for your particular vehicle. Your problem may be a known issue with a known manufacturer-released fix and could save you time and money while troubleshooting.

First, look for other DTCs. If any of these are bus communication or battery / ignition related, diagnose them first. Misdiagnosis is known to occur if you diagnose the U0104 code before any of the major codes are thoroughly diagnosed and rejected.

If your scan tool can access DTCs and the only code you are getting from other modules is U0104, try contacting the cruise control module. If you can access the codes from the CCM, then code U0104 is either intermittent or a memory code. If the CCM cannot be contacted, then code U0104 set by other modules is active and the problem already exists.

The most common failure is a loss of power or ground.

Check all fuses supplying the CCM on this vehicle. Check all the reasons for the CCM. Locate grounding attachment points on the vehicle and make sure these connections are clean and secure. If necessary, remove them, take a small wire bristle brush and baking soda / water solution and clean each one, both the connector and the place where it connects.

If any repairs have been made, clear the diagnostic trouble codes from all modules that set the code in memory and see if U0104 returns or you can contact the CC module. If no code is returned or communication with CCM is restored, the problem is most likely a fuse / connection issue.

If the code returns, look for the CAN bus connections on your specific vehicle, especially the CCM connector. Disconnect the negative battery cable before disconnecting the connector on the CCM. Once detected, visually inspect the connectors and wiring. Look for scratches, scuffs, exposed wires, burn marks, or molten plastic. Disconnect the connectors and carefully inspect the terminals (metal parts) inside the connectors. See if they look burnt or have a green tint indicating corrosion. If you need to clean the terminals, use an electrical contact cleaner and a plastic bristle brush. Allow to dry and apply dielectric silicone grease where the terminals touch.

Perform these few voltage checks before plugging the connectors back into the CCM. You will need access to a digital volt-ohmmeter (DVOM). Make sure the CCM has power and ground. Access the wiring diagram and determine where the primary power and ground supplies go into the CCM. Reconnect the battery before proceeding with the CCM still disabled. Connect the red wire of your voltmeter to each B + (battery voltage) power source going to the CCM connector, and the black wire of your voltmeter to a good ground (if unsure, the negative pole of the battery always works). You should see the battery voltage reading. Make sure you have a good reason. Connect the red lead from the voltmeter to battery positive (B +) and the black lead to each ground. Once again, you should see the battery voltage every time you plug it in. If not, troubleshoot the power or ground circuit.

Then check the two communication circuits. Locate CAN C+ (or HSCAN+) and CAN C- (or HSCAN - circuit). With the black wire of the voltmeter connected to a good ground, connect the red wire to CAN C+. With the key on and engine off, you should see about 2.6 volts with little fluctuation. Then connect the red wire of the voltmeter to the CAN C- circuit. You should see about 2.4 volts with little fluctuation.

If all tests pass and communication is still not possible, or you were unable to reset DTC U0104, the only thing to do is to seek help from a trained automotive diagnostician, as this will point to a faulty cruise control module. . Most CCMs must be programmed or calibrated for the vehicle in order to install correctly.

Related DTC discussions

  • U0104 Lost communication with cruise control moduleHi I am facing this error U0104 - Lost Communication with Cruise Control Module on my Octavia 2019 which cannot be erased. Error in the automatic transmission module. The error occurred after decalibrating the Front Assist module. The guys from the service reconfigured the Front Assist module ... 

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NOTE. This information is provided for informational purposes only. It is not intended to be used as a repair recommendation and we are not responsible for any action you take on any vehicle. All information on this site is protected by copyright.

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