Transmission Range Sensor "A" Circuit Range/Performance

What it means

The transmission range (TR) sensor is sending a signal that is electrically valid but does not make sense compared with other sensors. The transmission range (TR) sensor tells the computer which gear lever position (P, R, N, D) is selected. This usually points to a sensor that is reading wrong, or to a real mechanical problem it is reporting correctly, rather than a broken wire.

Symptoms

• Check engine light on
• Engine will not start in Park or Neutral, or starts in gear
• Wrong gear shown on the dashboard
• Reverse lights not working
• Erratic shifts

Probable causes

Most likely first

1. 1Sensor out of adjustment
2. 2Shift linkage worn or misadjusted
3. 3Failing sensor giving an inaccurate reading
4. 4Poor connection at the sensor connector

How to diagnose it

Work through these in order before buying parts

1. 1Record the code and its freeze frame data (speed, load, temperature when it set), then clear it and see if it comes back.
2. 2Inspect the transmission range (TR) sensor connector and wiring (on the side of the transmission where the shift linkage connects). Look for corrosion, bent or pushed-back pins, oil contamination and chafed insulation.
3. 3Watch the transmission range (TR) sensor reading on live data. Move the lever through every position and check the scan tool shows the correct range each time.
4. 4Compare the transmission range (TR) sensor reading against related sensors and the real-world condition. If they disagree, find out which one is telling the truth before buying parts.
5. 5If the wiring checks out, test the sensor itself against the specification in a service manual.
6. 6Check for technical service bulletins (TSBs) or software updates for your make and model; some codes have known factory fixes.

Common fixes

• Fix the underlying problem the sensor is reporting, if real
• Replace the transmission range (TR) sensor if it reads wrong against a known-good reference