U0001 - HIGH-SPEED COMMUNICATION AREA NETWORK BUS

The cars are equipped with control modules or computers, which communicate with each other via the CAN bus (Control Area Network).

The CAN bus has two lines: CAN high speed and CAN low speed. In the case of CAN high or high speed, it transmits data at 500k bits/second, and CAN low or low speed is 125k bits/second. To process and transmit messages between the two CAN buses, the Integrated Power Module (TIMP) is used. Each vehicle control module has an identification code with which the TIMP identifies the module that is communicating. This is known as binary conversation.

DTC code U0001 OBD2 indicates that a problem has occurred in the Control Area Network harness or connector or the Fully Integrated Power Module.

• Check Engine light illumination.
• The vehicle key alarm is intermittently activated.
• Several attempts are required to start the vehicle.
• The engine shuts down unexpectedly.

The reasons for setting the U0001 OBDII diagnostic code are:

• The Control Area Network may have an open or short circuit.
• Damage to the CAN bus harness.
• Low voltage due to a bad battery.
• Perhaps, there is a faulty control module.
• Possibly, a control module suffered a memory leak due to temporary power failure.
• The TIMP may be defective.

The steps to solve the U0001 OBD2 trouble code are:

• Consult your vehicle's service manual for the wiring of the Control Area Network, as well as the modules controlled by it. Then, with a scanner, operate each module independently to check if it is working or not.
• If a control module is not working properly, check the corresponding circuit and check for corroded, burned, or otherwise damaged connectors or wires. Also, check the battery for power with a voltmeter. Low power indicates damage to the connector or cables. Repair or replace as required.
• Check that the ground for the circuit is the necessary one. Repair if necessary.
• Use a scanner to check that the waveform matches the manufacturer's specifications. If not, the module may be defective.
• After disconnecting the Control Area Network from the Fully Integrated Power Module, check the connector. Connect the scanner to terminals 4 and 5 of the connector located on the top row counting from right to left. Then, turn on the motor and observe the waveform. The result should be compared to that indicated by the manufacturer. If there is a narrow margin of difference, replace the TIMP.