P2691 - OBD Trouble Code

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Is the car engine not performing at par with the expectations? Do you notice affected fuel economy, delayed throttle response and Check Engine Light illuminated on the dashboard? This can be an indication of a problem with the fuel injector of the vehicle, resulting in OBD code P2691 getting stored in the Powertrain Control Module (PCM).

When the cylinder 6 fuel injector data is incompatible with PCM, OBD code P2691 gets stored in the system.

Every fuel injector has a unique calibration ID that makes it unique to the Powertrain Control Module (PCM) and the Glow Plug Control Module (GPCM). This helps both the modules to know about the injector flow rate and cylinder position. OBD code P2691 can occur if both or one module is unable to identify the injector flow rate or the injector itself is at fault.

What causes this problem with the Cylinder 6 Injector Data Incompatible?

• Burnt or damaged injector wiring and harness
• Faulty fuel injector
• Faulty injector sensor and its circuit
• Faulty PCM and/or GPCM modules

1. Engine Control Module - Most of the time it is difficult to intercept the ECM faults and thus must be checked for thoroughly. There can be a problem with the circuit or the software might have malfunctioned. Thus repair, replace or reprogram the component as per requirement.
2. Fuel Injector – The fuel injectors are an important component of the fuel delivery system that helps in proper utilization of the fuel entering the engine. This not only helps in taking care of the air to fuel ratio in the engine, helping the combustion process but also enhances the performance. Thus, replace faulty injector now!
3. Injector Connector – Faulty injector connector can also cause the injector to malfunction and cause problem in communicating with the PCM. Thus, replace faulty connector now!
4. Powertrain Control Module - If the PCM is faulty, it can stores wrong OBD codes and can lead to misdiagnosis. This can happen due to misinterpretation of data received from the various sensors and components which also affects the vehicle’s performance. Thus replace it immediately.
5. Electronic Control Unit – If the ECU is at fault, it will not be able to read the boost converter temperatures correctly leading to underperformance. Thus, replace faulty ECU now!
6. Diagnostic Tool - Choose from our diagnostic tools collection that will come in handy to detect and correct the OBD error code.

It is essential to know the symptoms of an issue as only then you would be able to solve the problem. So that’s why we have listed out some major symptoms of OBD Code P2691 here:

Common Symptoms

• The service engine soon light can start lighting up
• Decrease in the overall fuel efficiency
• There might be a lot of black smoke coming out from vehicle exhaust
• The engine performance might start declining

Here are some ways with the help of which you will be able to correct the OBD Code P2691

• Make sure to mend faulty electrical connection
• It is essential to restore the flawed cylinder 6 fuel injector
• Rehabilitate the defaults in the wiring harness
• Carefully reprogram the PCM and GPCM

Don’t get tensed if you are still facing any of these issues as we care for our customers and that’s why we offer a good range of fuel injectors, PCM, glow plug control modules, detective fuel injectors, injectors connectors, damaged injector wiring, connectors, disconnected ground wires to the PCM and a lot more. We are sure that now all your issues would be resolved.

If you want to easily diagnose this fault code, then all you have to do is to follow the steps which are mentioned below:

• OBD error code P2691 occurs in the diesel engine powered vehicles. In many diesel engine vehicles, the fuel injectors have unique alphanumeric identification numbers that differentiate one injector from other.
• This unique code has been programmed in the CAN (Controller Area Network) for the system to identify and respond to each injector separately and function accordingly.
• The CAN acts as the brain and takes input from various sensors and thus takes appropriate actions and control functions of the vehicle.
• If this injector identification number in not recognised by the PCM, it might require reprogramming and the unique IDs must be restored in the system.
• A qualified mechanic will use a diagnostic scanner, a digital volt/ohmmeter (DVOM), and a source of vehicle specific diagnostic information to diagnose OBD code P2691.
• Make use of CAN bus system wiring and connector diagram and check for the CAN resistance to match with the manufacturer’s specification. If the CAN system output is not as per specification, it might be physically damaged and need replacement or simply might need reprogramming.
• Next, visually inspect the wiring harnesses and connectors in association with the injector, sensors and modules. Repair or replace burnt or damaged wiring and or connectors before doing any further diagnosis.
• Plug the scanner into the vehicle diagnostic connector and retrieve all stored codes and pertinent freeze frame data. Note this information down before clearing the fault codes. Make the PCM to go into readiness mode or reset the code by test driving the vehicle.
• With the help of the scanner, activate the fuel injector (solenoid) and test output control circuit voltage, if the power battery voltage and ground circuit are discovered appropriately.
• If the controller is bad or has experienced a programming error, if the voltage is insufficient, the controller might be bad. If the voltage output circuit is within parameters, use the DVOM and test the fuel injector and replace if faulty.

Common Mistakes When Diagnosing The P2691 Code

• Fuel injector failure
• Powertrain Control Module (PCM) failure
• Wiring and connector issues in relation to the sensor and circuits
• PCM or CAN programming error