What it means
The vehicle speed sensor B circuit signal is lower than expected. The cause may be the sensor, wiring, connector, or related circuit.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Vehicle speed sensor B supplies a speed signal to the control module for functions such as speed display and transmission control. P2160 sets when the signal in the sensor B circuit is lower than expected, often because the circuit is shorted to ground or has excessive resistance.
Common causes
Most likely first.
- Short to ground
- Connector pins corroded - high contact resistance
- Harness chafing through insulation
Symptoms
- Speedometer may read incorrectly or fluctuate
- Transmission shifting may be affected
- Cruise control may not work
- ABS or traction-control warning light may come on
How to diagnose it
- Review freeze-frame data and graph vehicle speed sensor B on a scan tool to confirm whether its signal is consistently low or drops out.
- Inspect sensor B's connector and harness, especially for chafing to ground, corrosion, bent pins, or water entry.
- Check the circuit for a short to ground and excessive connector resistance using the manufacturer's wiring information and specification.
- Test sensor B's output and supply or return circuits as applicable to the sensor design, following the manufacturer's procedure.
- If sensor B and wiring pass, check the module input and verify the vehicle's speed-signal configuration.
Common fixes
- Clean and secure corroded or loose sensor B connector terminals.
- Repair the harness where it is shorted to ground or chafed.
- Replace vehicle speed sensor B if its signal remains low despite a sound circuit.
- Repair a failed circuit connection or module input confirmed by testing.
Can I keep driving?
A low sensor B signal can make the speedometer unreliable and interfere with shifting, cruise control, or stability-related functions. Drive cautiously, avoid relying on cruise control, and stop if the vehicle's speed indication or shifting becomes unsafe.
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.