
U0157 Lost communication with information center B
Content
U0157 Lost communication with information center B
OBD-II DTC Datasheet
Lost connection with Call Center B
What does this mean?
This is a generic communication system diagnostic trouble code that applies to most makes and models of vehicles.
This code means that the Information Center "B" (IC-B) 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.
IC-B is usually located behind the dashboard, usually in the center of the vehicle. It accepts input data from various sensors, some of which are connected directly to it, and some are sent over a bus communication system. These inputs allow the module to display information centrally for easy viewing.
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 always serious because of the safety issues that arise from the IC-B being able to obstruct the driver's view.
Symptoms of a U0157 engine code may include:
- Info center A no info / blank screen
reasons
Usually the reason for installing this code is:
- Open in CAN + bus circuit
- CAN bus break - electrical circuit
- Short circuit to power in any CAN bus circuit
- Short to ground in any CAN bus circuit
- No power or ground to HUD module
- 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 U0157 code before any of the major codes are thoroughly diagnosed and rejected.
If your scan tool can access trouble codes and the only code you are getting from other modules is U0157, try accessing the IC-B. If you can access codes from the IC-B, then the U0157 code is either intermittent or a memory code. If you cannot access the IC-B, then the U0157 code that the other modules are setting is active and the problem already exists.
The most common fault is loss of power or grounding of IC-B.
Check all fuses supplying the IC-B module on this vehicle. Check all bases for IC-B. 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 DTCs from memory and see if U0157 returns or you can contact the IC-B module. If no code is returned or communication is restored, the problem is most likely a fuse / connection issue.
If the code returns, look for the CAN bus connections on your car, especially the IC-B connector, which is usually located behind the dashboard. Disconnect the negative battery cable before disconnecting the connector on the IC-B module. 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.
Before reconnecting the connectors to the IC-B, perform these few voltage checks. You will need access to a digital volt-ohm meter (DVOM). Make sure there is power and ground at the IC-B. Access the circuit diagram and determine where the main power and ground sources enter the IC-B. Reconnect the battery before continuing, with the IC-B still disconnected. Connect the red lead of your voltmeter to each B+ (battery voltage) source entering the IC-B connector, and the black lead of your voltmeter to a good ground (if unsure, the negative post of the battery always works). You should see a battery voltage reading. Make sure you have a good ground. Connect the red lead of your voltmeter to the positive (B+) terminal of the battery, and the black lead to each ground circuit. Once again, you should see battery voltage with each connection. If not, troubleshoot the power or ground circuit.
Next, check the two communication circuits. Find CAN B+ (or MSCAN+ circuit) and CAN B- (or MSCAN – circuit). With the black lead of the voltmeter connected to a good ground, connect the red lead to CAN B+. With the key on and the engine off, you should see about 0.5 volts with slight fluctuations. Then connect the red lead of the voltmeter to the CAN B circuit. You should see about 4.4 volts with slight fluctuations.
If all tests pass and communication is still not possible, or you were unable to clear the U0157 trouble code, the only thing to do is to seek help from a trained automotive diagnostician, as this would indicate a faulty IC-B. Most of these IC-Bs need to be programmed or calibrated to properly install the vehicle.
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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.

