Error Code P062E is defined as Internal Control Module EEPROM Error. This is a generic trouble code that applies to all vehicles with the OBD-II system. This usually includes models from Buick, Cadillac, Chevrolet, GMC, Ford, Honda, Mercedes Benz, Nissan, Subaru, Suzuki, etc. Specifications on the definition, troubleshooting, and repairs, of course, vary from one make and model to another.

When this code is stored, this means the PCM (powertrain control module, also known as ECM or engine control module in other vehicle makes) has found an internal performance error with the EEPROM (electronically erasable read-only memory). Additional controllers can also detect an internal PCM performance error (in fuel injection control system) and cause this code to be stored.

The Internal Control Module monitoring processors are responsible for different controller self-test duties and overall internal control module accountability. Both input and output signals of the Fuel Injection Control system is subjected to self-test, and are constantly being monitored by the PCM and other controllers. The TCM (transmission control module), TCSM (traction control module), and other controllers also interact with the EEPROM.

The EEPROM provides a way to read, erase, rewrite small amounts (bytes) of programmable memory. Using specific programming, the EEPROM (or any part of EEPROM) may be erased and rewritten in sequence. The EEPROM is a bank of transistors that consists of three parts. It’s typically removable, and locks to a socked specially designed inside the PCM. When defective PCM is replaced, the EEPROM is usually removed and reused for the new PCM. Both the PCM and EEPROM must be reprogrammed as a unit. The EEPROM may be capable of 1-million programming changes and designed to last for a hundred years, but it can be sensitive to moisture and excessive heat.

When the ignition is On, and the PCM is energized, the EEPROM conducts a self-test automatically. Aside from running internal controller self-tests, the CAN (controller area network) also compares signals from each module, ensuring each controller to function properly. These tests are performed simultaneously.

If the PCM sees discrepancies in the functionality of the EEPROM, it stores the Error Code P062F and activates the Check Engine light. If the PCM sees a problem between any of the onboard controllers, which indicates internal EEPROM error, the code will be stored as well. In some cases, depending on the perceived severity of the problem, multiple failure cycles may be needed for the Check Engine light to activate.

Common Symptoms

This code usually comes with wide range of drivability issues that affect the engine and transmission performance.

  • No start condition
  • Engine stalls or dies at idle
  • Increased fuel consumption
  • Lack of cooling fan operation

Possible Causes

  • Defective controller programming
  • PCM overheat
  • Water damage
  • Blown fuse
  • Bad controller power relay
  • Open or shorted circuit or connectors in CAN harness
  • Insufficient control module ground
  • Defective EEPROM

How to Check

This code is quite a challenging problem to diagnose, and many times, it involves reprogramming issues. Thus, without the right tools and reprogramming equipment, it will be impossible to replace a defective controller and complete the repair.

If the PCM power supply codes are present, then obviously, they don’t need to be rectified before attempting to diagnose this code.

Many preliminary tests can be performed prior to make sure a controller is defective. A diagnostic scanner, DVOM (digital volt/ohmmeter), and reliable vehicle information is needed for diagnosis of this code.

The first step is to connect the scanner to the vehicle diagnostic port and retrieve all stored codes, including their freeze frame data. You need to write down this information, just in case the problem proves to be intermittent. After writing down all pertinent information, clear the codes and then take the vehicle for a test drive to see if the code resets, or if the PCM enters readiness mode. If the PCM does the latter, then you have an intermittent problem, which is more difficult to diagnose, as it means you would have to wait for the problem to develop more before you can successfully diagnose.

If the code resets, however, then continue with your preliminary diagnosis.

When trying to diagnose this code, refer to your information source or TSB (technical service bulletin); looks for signs and symptoms parallel to the stored code. Search for the year, make, model, and engine of your vehicle. If you are able to find the right TSB, then you may get the best diagnostic information for your problem.

Use vehicle information source to obtain component locations, connector face views, connector pin-out charts, wiring diagram, and diagnostic flow chart related to your vehicle’s error code.

Then, use the DVOM to the test controller power supply fuses and relays. Next, test and replace any blown fuses as necessary. Fuses must be tested with circuit loaded.

If all fuses and relays are running well, check whether the controller related wiring and harness are in order. You may also want to check chassis and engine ground junctions. Again, use your vehicle information source to obtain ground locations as related circuits. Test ground integrity using the DVOM.

Then, check the system controllers for any signs of water, heat, or collision damage. Any controller that is damaged, especially by water, is considered defective and must be replaced.

If controller power and ground circuits are intact, then there’s a good chance the controller is defective, or there’s a programming error in the controller. Thus, controller replacement requires reprogramming. In some cases, you may want to get aftermarket reprogrammed controllers. Some vehicles and controllers require on-board reprogramming that may be done only through the dealership or a qualified shop.

How to Fix

  • Replacement of blown fuses
  • Replacement and reprogramming of defective controller
  • PCM replacement

Error Code P062F along with other fuel injection-related code must be classified as severe and must be addressed as soon as possible.