U0022 - FAULT CODE - OBD2

U0022 - LOW SPEED CAN COMMUNICATION BUS (+) LOW

The CAN bus (Control Area Network) is an automotive communication network that interconnects multiple devices without a central unit. The devices exchange various operating data and commands via this network. For each device, programmed data about the messages to be exchanged are included in the serial data circuits.

There are two lines for CAN bus communication. They are known as CAN low and CAN high, which have 2.5 volts each one at rest. When the data transmission starts, CAN low decreases its voltage to 1.25, and CAN high increases it to 3.75. There is a difference of 2.5 volts between the lines. This is because the basis of communication is the voltage difference between the two lines, taking into account t the CAN bus has no problems with inductive peaks or electronic fields.

The diagnostic code U0022 OBDII is stored when it does not receive a supervised periodic message containing the availability of the transmitting device or equipment.

• Check Engine light ON.

The storage of the DTC U0022 OBD2 code is set because of the following reasons:

• Various stored DTCs could cause U0022 to
• A control module may have deficiencies in its cables or connectors.
• A control module may be damaged.

Steps to troubleshoot the U0022 OBDII fault code:

• Consult the Technical Service Bulletins.
• Check with an automotive scanner if other codes are stored in addition to DTC U0022. If this is the case, the diagnosis of these codes must be done in the order indicated.
• Inspect all cables, connectors, and electrical connections of the control modules. If you discover deficiencies due to wear and tear or other damage, make the necessary repairs.