Description of fault code P0117,
OBD2 Error Codes

U010C Lost Communication With Turbocharger / Supercharger Control Module A

U010C Lost Communication With Turbocharger / Supercharger Control Module A

OBD-II DTC Datasheet

Lost Communication With Turbocharger / Supercharger Control Module A

What does this mean?

This is a generic communications system diagnostic trouble code that applies to most makes and models of OBD-II vehicles.

This code means the Turbocharger / Supercharger Control Module A (TSCM-A) 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.

Modules communicate with each other over a network, just like the network you have at home or work. Car manufacturers use several networked systems. Prior to 2004, the most common (non-exhaustive) inter-module communication systems were the serial communication interface, or SCI; SAE J1850 or PCI bus; and Chrysler Collision Detection, or CCD. The most common system used after 2004 is known as Controller Area Network communication, or simply the CAN bus (also used until 2004 on a small segment of vehicles). Without this CAN bus, control modules cannot communicate and your scan tool may or may not receive information from the vehicle, depending on which circuit is affected.

The Turbocharger / Supercharger Control Module A (TSCM-A) is usually located under the hood, either on the fender or on the bulkhead. It receives input from a variety of sensors, some of which are directly connected to it, and most are transmitted over a bus communication system from the powertrain control module (PCM). These inputs allow the module to control when the turbocharger / supercharger is boosting, bypassing, or in diesel applications, when it will control the turbocharger as a heat riser valve to raise the exhaust gas temperature under certain conditions.

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.

Code severity and symptoms

The severity in this case is not serious because PCM has a backup strategy in case it loses communication with TSCM-A.

Symptoms of a U010C code may include:

  • Malfunction Indicator Light (MIL) "On"
  • The engine may show a lack of power
  • It can operate normally in cold weather, but when the engine is warm, it can start knocking when accelerating.
  • The engine can start and run, but not when the engine is cold.

reasons

Usually the reason for installing this code is:

  • Open on CAN bus + or - circuit
  • Short to ground or ground in any CAN bus circuit
  • No power or ground to TSCM-A
  • Rarely - the control module is faulty

Diagnostic and repair procedures

A good place to start with ALL electrical diagnostics is to check the Technical Service Bulletins (TSB) for your vehicle. The problem you are facing may be known to others in the field. A known fix may have been released by the manufacturer and can save you time and money during diagnostics.

It is assumed that a code reader is available to you at this point, as you may have been able to access the codes up until now. See if there were any other DTCs related to bus communication or battery / ignition. If so, you should diagnose them first, as misdiagnosis is known to occur if you diagnose the U010C code before any of the underlying codes are thoroughly diagnosed and corrected.

If the only code you get from other modules is U010C, try accessing TSCM-A. If you can access codes from TSCM-A then code U010C is either intermittent or memory code. If you cannot access TSCM-A, then the code U010C that other modules install is active and the problem already exists.

The most common fault is a circuit fault that results in a loss of power or ground to the turbocharger/supercharger control module a.

Check all fuses supplying the TSCM-A on this vehicle. Check all the grounds for TSCM-A. Locate ground anchorage 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 DTCs from all modules that set the code in memory and see if you can now communicate with the TSCM-A module. If communication with the TSCM-A recovers, the problem is most likely a fuse / connection issue.

If the code returns or communication still cannot be established with the module, locate the CAN bus communication connections on your vehicle, most importantly the TSCM-A connector, which is usually found under the hood on the fenders or on the bulkhead. Disconnect the negative battery cable before disconnecting the connector on the TSCM-A. Once found, 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 electrical grease where the terminals touch.

Perform these few voltage checks before reconnecting the connectors to the TSCM-A. You will need access to a digital volt ohm meter (DVOM). Make sure the TSCM-A is powered and grounded. Access the wiring diagram and determine where the main power and ground supplies enter the TSCM-A. Connect the battery before proceeding with the TSCM-A still disconnected. Connect the red lead of your voltmeter to each B + (battery voltage) power source going into the TSCM-A connector, and the black lead 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. Other manufacturers show CAN C- at about 5V and an oscillating key with the engine off. Check your manufacturer's specifications.

If all tests pass and communication is still not possible, or you were unable to clear DTC U010C, the only thing that can be done is to seek help from a trained automotive diagnostician, as this will indicate a TSCM-A failure. . Most of these TSCM-A's must be programmed or calibrated in order to properly install the vehicle.

Related DTC discussions

  • Code U010C on Ram 6.7L Turbocharged CumminsI recently had a few reviews of my 2014 3500 Ram. The DEF SCR has been replaced and the passenger safety control (ORC) module has been reprogrammed. Since this was completed, I am getting error code U010C (Lost communication with Turbocharger / Supercharger control module "A"). Could ... 

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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.

One comment

  • Matias

    I have a 6.7 Cummings ram and I changed the module. Could it be that I have to regulate it or program it?

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