P2803
Transmission Range Sensor B Circuit High
Transmission controls
Generic OBD-II
Medium
What it means
P2803 sets when the transmission range sensor's "B" circuit reads higher than expected, so the controller can't reliably tell which gear the shifter is in. Because this sensor feeds the neutral-safety and shift logic, it can cause a no-start in Park/Neutral, a wrong-gear start, a bad gear-position display, or limp mode. It's usually a sensor, adjustment, or wiring fault.
Medium
Can I keep driving? Often drivable but unpredictable — the transmission may not know the selected gear, causing no-start in Park/Neutral, wrong-gear starts, or limp mode.
Common symptoms
What you'll notice
- Check-engine light on
- No-crank or hard start (neutral-safety logic doesn't see Park/Neutral)
- Gear indicator (PRNDL) blank, wrong, or flickering
- Harsh or delayed engagement, or the transmission defaulting to a fixed gear
Common causes
Most likely first
- Faulty transmission range sensor (B circuit)Likely
- Misadjusted range sensor / manual-lever position out of alignmentCommon
- Range-sensor circuit shorted high or open in the harnessCommon
- Corroded or loose connector at the range sensorLess often
- Faulty TCM/PCM input (least likely)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame and confirm the reported range versus the actual shifter position.
- Inspect the range-sensor connector and wiring for damage, corrosion, or a high-side short/open.
- Check range-sensor adjustment/alignment to the manual shift lever.
- Measure the sensor signal through all gear positions against the service values; replace if out of range.
- Clear the code and verify correct gear reporting and normal starting.
FAQ
Quick answers
Is it safe to drive with P2803?+
It can leave the car unable to start in Park or starting in the wrong gear, and it may enter limp mode. It's drivable in some cases, but get it fixed soon to avoid being stranded.
Can I just clear P2803?+
Clearing helps confirm the fault, but if the range sensor or its wiring is bad the code and symptoms return. Repair the circuit.
Related codes
Often seen with P2803
Read & clear P2803 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