Multi-code OBD2 diagnosis
Enter all the codes your scanner showed, not just the first one. We give you the overall severity, whether you can keep driving, the order in which to check them and how they relate to each other.
Summary
- Overall severity
- High
- Can I keep driving?
- Yes, but with caution
- Estimated cost
- $0 to $1,500
- Codes analyzed
- 1 of 1
The order below is the recommended one: first the codes that can cause the others. After each repair, clear the codes and check which ones come back.
Order of inspection
U0021 Low Speed CAN Communication Bus (+) Open High
The U0021 code means the computer detected an open circuit on the low speed CAN bus (+) wire. It usually sets communication codes in several modules and, depending on the network affected, limp mode or a dash full of warning lights. With one wire open, the network may keep working partway or stop working beyond the break.