This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.
U0155 is an OBD-II Code that refers to Lost Communication With Instrument Panel Cluster Control Module
A U0155 code is a generic communication systems diagnostic trouble code that indicates that there’s a loss of communication with your Instrument Panel Cluster Control Module (IPC). When the Powertrain Control Module (PCM) can no longer talk to the IPC properly, this is known as a CAN bus fault. An error code U0155 might indicate that the PCM is unable to communicate with other control modules in the system.
Common causes for this code include:
- Communication Issues within modules
- Bad Instrument Panel Cluster Control Module
- Instrument Panel Cluster Control Module circuit poor electrical connection
- Instrument Panel Cluster Control Module harness is open or shorted
The symptoms of a U0155 code are:
- Malfunction Indicator Lamp (MIL) on
- All indicator lights on the instrument panel and cluster are illuminated.
- No indicator lights on in instrument panel / cluster
To diagnose a U0155 DTC code, a technician would:
- Check for communication issues between modules
- Check battery voltage for proper levels
- Check for communication issues between the PCM and IPC
- Check DTC's history; see if this is a current or former (resolved) issue
- Check all wiring connections, make sure they’re tight and not corroded.
- Diagnose any other problems found using freeze frame data and check related systems
The following are some of the most common mistakes that a technician may make when diagnosing a U0155 code:
- Not using the proper diagnostic test equipment
- Not checking freeze frame data and checking for DTC’s only
- Not following proper repair procedures
- Not using a factory shop manual
How serious is this?
A U0155 code is considered to be and can cause severe issues with your car. If this bridge of data transfer no longer exists, it means that other control modules aren’t able to communicate with the PCM as well. This loss of communication means that the PCM cannot monitor the operation of vital control modules that your vehicle depends on to operate efficiently.
What repairs can fix the code?
The following are solutions that may fix this problem:
- Replace the IPC
- Replace the faulty wire(s)
- Repair any corrosion
- Replace the PCM
- Cleaning and correction of Battery Terminals
A U0155 is related to and may be accompanied by the following codes:
U0103 – Lost Communication With Transfer Case Control Module (TCCM)
In conclusion, the U0155 code is a communication error between the Powertrain Control Module (PCM) and the Instrument Panel Cluster (IPC) control module. If you are experiencing this code, make sure to check out the other related codes listed above in addition to troubleshooting your issue using Repair Manuals or Technical Service Bulletins.