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
- $20 to $900
- 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
P0866 TCM Communication Circuit High High
The P0866 code means the communication line to the transmission control module (TCM) is reading high. The transmission may go into limp mode, or the shifter may stop responding. An open line or a short to voltage is the usual cause.