Code result
P27B1
Internal Control Module Transmission Range Select Performance
High severity
What it means
The internal range-select interpretation logic in the transmission control module does not match external sensor inputs.
Is it safe to drive?
No — stop driving
This code points to a problem that can cause damage or affect safety. Avoid driving and have the vehicle diagnosed promptly.
Most likely causes
Internal logic drift after firmware update
mediumA plausible cause — test and verify before replacing parts.
External range sensor drift
mediumA plausible cause — test and verify before replacing parts.
Related help
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