OBD Guide

U0035

Vehicle Communication Bus A (-) High

U0035 is an OBD-II diagnostic trouble code meaning: Vehicle Communication Bus A (-) High. Common causes: open or short circuit in the can-a high line, poor contact in can bus connectors. Estimated repair cost: $6–56.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$6–56 (est.)

Symptoms

  • Check Engine light comes on
  • Incorrect operation of electronic systems
  • Lost connection with some modules
  • Problems with diagnostics via OBD-II

Causes

  • Open or short circuit in the CAN-A High line
  • Poor contact in CAN bus connectors
  • Malfunction of one of the electronic modules
  • Wiring harness damage
  • Contact corrosion

How to Fix

  1. Check the integrity of the CAN bus wires
  2. Inspect connectors for oxidation or damage
  3. Check the resistance of the CAN bus (should be about 60 ohms)
  4. Disable the modules one by one to find the faulty one.
  5. If necessary, replace damaged wires or connectors

Related codes

Error U0035 by Vehicle Brand

FAQ

What does the U0035 code mean?

U0035 is an OBD-II diagnostic trouble code that indicates: Vehicle Communication Bus A (-) High

What causes a U0035 error code?

The most common causes of U0035 include: Open or short circuit in the CAN-A High line; Poor contact in CAN bus connectors; Malfunction of one of the electronic modules; Wiring harness damage.

How do I fix a U0035 diagnostic trouble code?

To fix U0035: Check the integrity of the CAN bus wires. Inspect connectors for oxidation or damage. Check the resistance of the CAN bus (should be about 60 ohms). For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U0035?

Yes, but get it checked soon

How much does it cost to fix U0035?

The estimated repair cost for U0035 is $6–56. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat