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P0606 – What Does It Mean and How To Fix It

This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.


Problem in Power Control Module (PCM).


The error code P0606 appears when there is a problem in your vehicle’s Power Control Module (PCM). The PCM is an inbuilt programmable computer in your car’s engine, which controls all electronic devices and functions. When a driver starts the car’s engine, the PCM runs all internal checks for 02 sensors, pressure sensors, and an automatic transmission system. Power Control Module (PCM) is a vital integrated element of your car’s engine, which needs to be maintained and checked before every drive. The Power Control Module also runs self-tests to ensure its working efficiently. When the PCM detects an internal problem, it pops up the code P0606. The occurrence of error code P0606 has multiple causes that can impact your engine’s mechanical and electrical capabilities. 

The DTC error code P0606 causes multiple problems in your car’s automated and manual systems. The error code P0606 pops up and illuminates the engine check light in your dashboard, which directly indicates an error or malfunction. 


The error code P0606 fundamentally appears when there is an immediate fault in your Car’s PCM. Your car’s smooth transmission and drive depend upon error-free PCM and engine systems. To find out the root cause of error code P0606, you need to evaluate multiple potential reasons.

Listed below are the possible causes that might trigger error code P0606.

  • Damaged and corroded circuit wires that cause short circuits
  • Damaged or malfunctioned connectors
  • Faulty ground circuit wiring
  • Problem in Control Area Network (CAN)
  • Computer glitch (software problem) causing failure in PCM’s firewall

Also read: How To Reset Car Computer Without Disconnecting The Battery?


While driving, you might notice the check engine light illuminates and gives error code P0606 warning. Moreover, you might experience multiple problems while driving your vehicle caused due to error code P0606. Mentioned below are the likely problems that one may experience:

  • Illuminated check engine light
  • Anti-lock Brake System (ABS) warning light illuminates
  • Imbalanced vehicle movements
  • Problem in ignition
  • Vehicle might undergo misfiring symptoms
  • Increased fuel consumption
  • Power failure while the vehicle is decelerating and coming to a stop


While examining the vehicle, one should closely check all components wired to the main Power Control Module (PCM). Moreover, the driver will also be notified as the car engine’s self-check light starts to glow in your dashboard. The driver should conduct a preliminary self-analysis by taking help from the user manual of the car. The self-diagnosis may include the following steps:

  • Check the entire circuits and wiring connected to PCM
  • Ensure that the plugs and connectors are tightly connected
  • Check for accumulated carbon or soot in connectors and plugs
  • Replace the wire connecting the Control Area Network (CAN) and Power Control Module (PCM)
  • Try to look for frayed wirings that might be causing circuit breaks

An experienced mechanic or an auto technician starts his preliminary analysis for the error code P0606 by searching for the root cause that has affected your car engine’s PCM. Moreover, the mechanic would scan through the engine’s wiring components, which might have caused a short circuit in your PCM’s mainframe. The mechanic or the motor-technician would start his analysis and follow the below-mentioned steps to diagnose the problem causing the DTC error code P0606. 

  • The mechanic would be using an OBD-II Scanner which would freeze the previous data and readings. The frozen data frame would provide the exact information regarding the error code ,  P0606. With this, the mechanic would be able to easily deduce the initial problems or the root cause which produced the error code P0606.
  • After scanning the PCM with an OBD-II scanner, the mechanic would visually check the wiring connections of the braking system, PCM, and other inter-connected circuits. It is imperative to check for frayed wires and other circuits closely attached to PCM and other vital functioning components.
  • After the in-depth analysis of the Power Control Module (PCM), the mechanic would reset the PCM’s mainframe system and restart the vehicle. After replacing the damaged wiring and circuits, if the PCM works perfectly fine, there would be no need to replace the whole PCM system.
  • If the PCM is still causing multiple problems and producing the error code P0606, it needs to be replaced.

Common mistakes

If the error code P0606 occurs, there’s a fair chance that your car’s PCM is damaged. Moreover, the error code P0606 is impossible to misdiagnose as the error code is relatively straightforward and self-explanatory. However, before replacing the PCM, one can visit a qualified mechanic or an automotive electrician to inspect all wiring and other elements. While resolving the error code P0606, the relevant mechanical and electrical failures should also be addressed, which were creating problems in the engine at the time of ignition. 

How Serious is P0603?

Power Control Module (PCM) is a vital component of your car’s engine. PCM controls all the functions and integrated connections that power your braking systems, ignitions, air sensors, and other primary components. If there is a fault in PCM, it will impact your vehicle’s overall performance and efficiency.

How to Fix This?

It is imperative to resolve the error code P0606 as soon as possible to avoid any serious damage to the engine and other mechanical parts. The PCM needs to be in the perfect shape to ensure smooth engine performance. To eliminate the error code P0606, you would typically need to replace your engine’s PCM mainframe system and conduct a detailed inspection of your vehicle.


It is recommended to monitor your car’s overall performance and fitness on a regular basis. Moreover, when you detect the error code P0606, you should immediately consult with an expert auto technician to get the right advice. In most cases, the entire PCM mainframe has to be replaced, but it should be done after a thorough inspection. Most car drivers try to sort this error code by replacing wires attached to the ignition; however, they should consult an experienced auto-technician who would scan the entire mainframe using the OBD-II Scanner. The error code P0606 needs to be resolved on an urgent basis as it affects the overall functioning of your car. 

P0606 – What Does It Mean and How To Fix It