P2804
Transmission Range Sensor B Circuit Intermittent
Transmission range sensor
Generic OBD-II
Medium
What it means
P2804 means the transmission range (PRNDL) sensor 'B' signal — which tells the controller and the starter system which gear the selector is in — is dropping out intermittently. It's usually a wiring, connector, or sensor-adjustment problem. Because the range signal affects starting and shift scheduling, it can cause wrong-gear shifts, limp mode, or an occasional no-crank.
Medium
Can I keep driving? Sometimes — an intermittent range signal can cause wrong-gear starts, harsh shifts, limp mode, or occasionally a no-crank; get it checked promptly.
Common symptoms
What you'll notice
- Check-engine light on, sometimes with a gear-indicator mismatch
- Harsh, delayed, or wrong-gear shifts
- Intermittent no-crank, or starts only in Neutral
- Transmission occasionally drops into limp/failsafe mode
Common causes
Most likely first
- Intermittent fault or misadjustment in the transmission range (PRNDL) sensorLikely
- Loose, corroded, or backed-out connector at the sensorCommon
- Chafed or intermittently open/shorted wiring in the range-sensor circuitCommon
- Worn manual-lever shaft or linkage moving the sensor out of positionLess often
- Transmission control module fault (least likely)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and note the conditions when the intermittent fault set.
- Wiggle-test the range-sensor connector and harness while watching the gear PID for dropouts.
- Inspect and reseat the connector; repair corroded or chafed wiring.
- Verify the sensor is correctly adjusted to the shift linkage.
- If the signal still drops out, replace the range sensor. Clear and re-test through all gears.
FAQ
Quick answers
Is it safe to drive with P2804?+
Drive with caution. Intermittent range faults can cause harsh or wrong-gear shifts and even a no-start, so it's best diagnosed before it strands you.
Can I just clear P2804?+
It typically comes back once the intermittent connection or sensor acts up again. Find and fix the loose connection or sensor instead.
Related codes
Often seen with P2804
Read & clear P2804 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX