Error Code P062B is defined as Internal Control Module Fuel Injector Control Performance. This is a generic trouble code, meaning it applies to all vehicles equipped with the OBD-II system. This includes but not limited to vehicles from Buick, Chevrolet, Citroen, Ford, GMC, Land Rover, Maserati, Mazda, Nissan, etc. Specifications on the definition, troubleshooting, and repairs, of course, vary from one make and model to another.
When Error Code P062B is stored, that means the PCM (powertrain control module, also known as ECM or engine control module in other vehicle makes) has detected an internal performance error in the fuel injection control system. 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 are subject to the interaction of the fuel injection control system.
The fuel injector controller is usually integrated into the PCM. There’s at least one fuel injector for every cylinder used to deliver a precise amount of fuel to the cylinder as the exact instant required to maximize both efficiency and performance.
Each fuel injector is like a type of solenoid that opens or closes using battery voltage. When the ignition is On, the constant battery voltage is supplied to each fuel injector. To complete the circuit and allow each fuel injector to spray a precise amount of fuel at the right time, the PCM supplies instant ground pulse.
The PCM uses the input signals from the CKP (crankshaft position) sensor and the CMP (camshaft position) sensor, the O2 (oxygen) sensor, MAF (mass airflow) sensor, and TPS (throttle position) sensor to monitor the performance of the fuel injector controller.
Every time the ignition is turned On, and the PCM is energized, the self-test for fuel injection control system will initiate. Simultaneously, CAN (controller area network) will also compare signals from each module to ensure each controller is working properly.
If the PCM sees any discrepancies within the internal fuel injector control system, the Error Code P062B will be stored, and activate the Check Engine light. Also, if the PCM detects a discrepancy between any other onboard controllers, which would indicate an internal fuel injector controller error, this 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.
- Engine misfire
- Misfire codes stored
- Hesitation upon acceleration
- Excessive lean or rich exhaust
Multiple factors could lead to this code, such as:
- Programming error
- Defective controller
- Open or shorted circuit or connectors in CAN harness
- Insufficient control module ground
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
Depending on your diagnosis, possible repairs include:
- Replacement of blown fuses
- Replacement and reprogramming of defective controller
Unlike most codes, this code is likely caused by a defective controller or a programming error in the controller.
Test the integrity of the system ground by connecting the negative test lead of DVOM to the ground, and the positive test lead to battery voltage.