Q: Knock sensor code

asked by on

Just a check engine light

My car has 148400 miles.
My car has an automatic transmission.

Hello. Knock sensors play a large roll in how the PCM (powertrain control module) times the spark. If excessive knock is present from the combustion cycle, the knock sensor will retard timing and attempt to correct it. The opposite is also true, if the knock sensor detects low input values, it can speed up the timing. When you are receiving a warning light and code for the knock sensor, the computer is telling you the sensor is not computing true values. This can be due to the sensor being bad, the wiring for the sensor being bad, a poor connection, or at worst a faulty PCM. You will simply need to replace the sensor(s). If the sensor has been replaced and the error code is still present, you will want to check the wiring and the connections. Although the wiring and connections are less likely to fail than the sensor, it is possible. Start by replacing the sensor, there is a strong chance its to blame, and check the wiring if that doesn’t solve the problem.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. Knock sensor code

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Q: Car shakes when I slow down.

Hello. The imbalance of rotating parts on a car, such as your wheel and tire assemblies, is a function of speed but also "positioning". When you were traveling at a steady state rate, say 65 MPH, the suspension was clearly...

Q: Q: Iac

This can be caused by the main engine computer has the IAC shorted full open or there is a short in the wiring to the IAC that holds it open. If you do not get any codes or do get...

Q: My car shakes sometimes at a stop light, reduced engine peeformance and just recently went into limp mode also check engine light

It's hard to tell without doing some further testing. This sounds like a misfire. A misfire can be caused by several components. It would explain the "limp mode", the shaking, and the Check Engine Light. Misfires are caused by...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.