What it means
The fourth transmission fluid temperature sensor reading is implausible. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
How it works
Transmission fluid temperature sensor D measures fluid temperature at a fourth sensing point in the transmission. The control module compares its signal with the expected temperature range and with other available temperature information; this code sets when sensor D reports a value that does not behave plausibly.
Common causes
Most likely first.
- Sensor drift after thermal aging
- Sensor not seated properly in the fluid path
- Sensor element aged beyond calibration window
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
- Read freeze-frame data and live transmission temperature readings to see whether sensor D is implausible or changes inconsistently with the other readings.
- With the transmission cool, compare sensor D's reading with ambient and other temperature readings for a sensible starting point.
- Inspect sensor D's connector and harness along the transmission for chafing, moisture, damaged seals, corrosion, or pushed-back pins.
- Wiggle the sensor D harness while watching its live reading to check for a change that points to an intermittent connection.
- If the wiring checks out, test sensor D and its circuit against the manufacturer's specification, including whether the sensor is seated in the fluid path.
Common fixes
- Reconnect and secure sensor D's connector.
- Repair chafed wiring or damaged connector seals and pins in the sensor D circuit.
- Correct sensor D's seating in the fluid path.
- Replace sensor D if its reading remains implausible after the circuit and installation checks.
Can I keep driving?
If shifts are harsh, delayed, slipping, or the transmission enters limp mode, avoid towing, hard acceleration, and long trips; stop if it slips badly or cannot shift safely. Continued driving with unreliable temperature information can lead to poor shift control and added transmission wear.
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.