P2159

Vehicle Speed Sensor B Circuit Range/Performance

Vehicle speed / idle control Generic OBD-II Medium

What it means

P2159 means the second vehicle speed sensor's signal is present but not tracking correctly against expected values. The ECM uses road speed for shift scheduling, the speedometer, and cruise control, so a bad reading shows up as erratic shifts, a jumpy speedometer, or disabled cruise. It's usually a sensor, wiring, or tone-ring issue and does not stop the engine from starting.

Medium

Can I keep driving? The engine runs, but a bad speed signal can cause erratic shifting, an inaccurate speedometer, and disabled cruise control — driveable with care, fix soon.

Real-world scan data

Seen in

431

scans in the past year

Found in

0.1%

of scans

0.1%

of scans that found faults

Appears alongside · share of P2159 scans

C1622in 51.5% of scans

C1203in 27.8% of scans

P0300in 17.2% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Erratic or inaccurate speedometer
Harsh, delayed, or erratic transmission shifts
Cruise control disabled
Possible ABS/traction control warning light

Common causes

Most likely first

Faulty vehicle speed sensor BLikely
Open or shorted wiring in the speed sensor circuitCommon
Poor or corroded connector at the sensorCommon
Damaged reluctor/tone ring the sensor readsLess often

How to diagnose & fix

Work through it in order

Read freeze-frame data and compare speed sensor B's reading to actual road speed in live data.
Inspect the sensor connector and wiring for corrosion, damage, or a loose pin.
Check the sensor's signal, power, and ground; inspect the tone/reluctor ring for damage or debris.
Replace the vehicle speed sensor if the signal is out of range with good wiring.

FAQ

Quick answers

Is it safe to drive with P2159?+

Generally yes for short trips, but the speedometer may read wrong and the transmission can shift oddly, so drive conservatively until it's repaired.

Can I just clear P2159?+

It will reset once the sensor signal is out of range again. Fix the sensor or its wiring, then clear and confirm the reading tracks true road speed.

Read & clear P2159 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX