03020 - Local databus 2
From Ross-Tech Wiki
03020 - Local databus 2: Electrical Fault in Circuit
Possible Symptoms
- Warning lights or messages in Instrument Cluster
- Feature(s) of vehicle inoperative.
Possible Causes
- Wiring Harness Issue
- Failed Electronics
Possible Solutions
- Repair Repair Wiring Harness
- Replace Failed Electronics
Special Notes
- When this fault code is flagged, it is important to check other control modules for fault codes. Different slave modules for different systems may be on the same bus (wire), thus one failed item causes several other items no longer perform to factory design.
- When found in the PQ25 BCM or BCM25 platform 09-Cent. Elect. (J519) module, make sure to check ALL subsystems including Door wiring harnesses, Door control modules, Sunroof motors and Multi-Function Steering Wheel module which could crash the LIN Bus. This thread contains an example from a 2014 NAR/Canadian market Jetta with photos of the damage found: 2014 jetta Horn not working
- When found in the BCM1 module of a MLB platform vehicle:
- Make sure the Refrigerant Temperature and Pressure Sensor (G395) is OK. That sensor is a is a LIN slave of J519 and they had a high failure rate. Data from G395 should be shown in Measuring Block Group 023 when the Local databus is functioning properly with a good sensor installed.
- If the vehicle was involved in a collision make sure the J530 (Garage door opener control module) and the wiring to it wasn't damaged. In most cases G395, G238/G657 and J530 are on the same splice point: B549 - LIN bus connection 2
- Official Factory Repair Information including wiring diagrams can be obtained through the links on this page.