Code U0035 indicates that the vehicle's Controller Area Network (CAN) bus is detecting a voltage level higher than the normal operating range. This typically signifies a short circuit to a power source or a failure in the network's terminating resistors.
A short between the CAN High line and a 12V power source due to chafed or damaged wiring.
An open circuit or failure in one of the network's termination resistors, causing signal voltage instability.
Moisture or corrosion in a module connector causing a bridge between power pins and communication pins.
An internal hardware failure within a peripheral module (e.g., ABS or BCM) that is pulling the bus voltage high.
A failure in the engine control module's communication transceiver.
No. U0035 is most frequently caused by wiring shorts or faulty peripheral modules. Replacing the PCM without verifying a wiring fault is usually an incorrect and expensive mistake.
While low voltage can cause communication errors, U0035 specifically refers to the voltage being too high, which usually indicates a short to power rather than a discharged battery.
It is not recommended, as a communication bus failure can disable critical safety systems such as the airbags, ABS, and electronic stability control.