Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. P2161 OBD-II Trouble Code: Vehicle Speed Sensor B Intermittent/Erratic

P2161 OBD-II Trouble Code: Vehicle Speed Sensor B Intermittent/Erratic

diagnostic check engine light logo

P2161 trouble code definition

Vehicle Speed Sensor B Intermittent/Erratic

What the P2161 code means

P2161 is an OBD-II generic code for the engine control module (ECM) detecting the vehicle speed sensor 2 or B giving an intermittent or erratic voltage output.

What causes the P2161 code?

The engine control module is getting a voltage return from the vehicle speed sensor 2 or B that does not correspond with the speed sensor 1 or A. The sensor may not be giving a steady voltage increase or decrease with speed and may be jumping around indicating a problem.

What are the symptoms of the P2161 code?

  • The Check Engine Light will be illuminated and the code is set in ECM memory as a fault.

  • The transmission and transfer case will have shift issues or shift timing issues.

How does a mechanic diagnose the P2161 code?

  • Scans and documents the code in the ECM to check the freeze frame data for failure

  • Drives the vehicle to confirm the output speed of the speed sensors and compares the data

  • Diagnoses and repairs codes P2161 by looking at the scan data of the speed sensor to see if it is sending the same speed signal as sensor A or 1

  • Checks the sensor for damage to the sensor itself or wiring

Common mistakes when diagnosing the P2161 code

  • Clearing ECM memory codes before checking the freeze frame data for the main failure problem, so the failure may be duplicated and repaired

  • Failing to clear the ECM codes after the codes are fixed

  • Failing to check the sensor reluctor ring for damage before replacing the sensor

How serious is the P2161 code?

Code P2161 is an indication that the ECM detects one of the two speed sensors needed to shift the transmission and transfer case properly is not working as needed and may cause transmission shifting problems.

What repairs can fix the P2161 code?

  • Replacing the speed sensor B or 2
  • Repairing an open or short in the sensor return wiring or connector
  • Replacing a broken sensor reluctor

Additional comments for consideration regarding the P2161 code

Code P2161 is for a second speed sensor and is in the transfer case on some vehicles to determine the transfer case gear speeds.

Need help with a P2161 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

Symptoms of a Bad or Failing Flexible Clutch Hose
Common signs include difficulty shifting, low clutch fluid, and feeling no resistance at the clutch pedal.
Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
How to Transfer a Car Title in Idaho
In order to prove ownership of a car, you must have the title. However, when a car is sold, given away or inherited, the title needs...


Related questions

Q: Why would i keep getting p0013 and p0023 codes when the truck isn't equipped with exhaust cams, it's not a 4 cam engine

Hello - this engine, although single overhead camshaft, does use variable cam timing, actuated by "cam torque", rather than engine oil pressure, to adjust exhaust valve timing (relative to the intake valves). This engine was introduced to Ford trucks in...

Q: Engine won't turn on, all light on

I'm working on this

Q: Code is P02990 what does it mean?

Hello, thanks for writing in about your Buick Cascada. Trouble code P0990 is a transmission fluid pressure fault. Possibly an internal fault in the transmission or there is a fluid leak. If the car didn't make it home, I suggest...