What it means
The TCM has not learned the calibration window for transmission range sensor B. Selector positions cannot be mapped reliably until adaptation completes.
At a glance
- Usually lights the check-engine light
How it works
Transmission range sensor B supplies selector position information that the transmission control module uses to identify the chosen transmission range. This code sets when the module has not learned sensor B’s calibration window, leaving it unable to map that sensor’s readings reliably to selector positions.
Common causes
Most likely first.
- Range sensor or related component replaced without completing its learn procedure
- Learn procedure interrupted or unsuccessful
- Range sensor wiring, connector, or adjustment fault
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Check freeze-frame and repair history for a recent replacement or adjustment involving range sensor B or its related components.
- Watch live range-sensor B data while moving the selector through its positions and note readings that fail to track the selected range.
- Inspect sensor B’s connector and harness for loose pins, corrosion, damage, or signs of misalignment.
- Check sensor B’s installation and adjustment against the manufacturer's procedure before starting calibration.
- If the readings and installation are sound, perform the manufacturer's sensor B learn procedure and verify the fault stays cleared.
Common fixes
- Complete the manufacturer's learn procedure for transmission range sensor B if its calibration was not completed.
- Repair damaged wiring or connector pins serving sensor B.
- Correct sensor B’s installation or adjustment using the manufacturer's procedure.
- Replace sensor B if it continues to report unstable or incorrect positions after circuit checks.
Can I keep driving?
Use the vehicle only if it recognizes the selected range and shifts normally; avoid situations where a delayed or missing shift could leave you unable to accelerate as expected. Stop safely if it slips, selects an unexpected range, or becomes stuck in one gear.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.