Error Code P2799: What It Means & What To Do?

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The trouble code P2799 can be elucidated as Auxiliary Transmission Fluid Pump Control Circuit High. The fluid is pressurized in the transmission with the help of auxiliary transmission fluid pump. Now if the pump would not operate as per the request, then P2799 fault code would be stored.

Want to learn something more about the P2799 fault code? There is a motor driver in the drive motor generator power inverter control module which controls the auxiliary transmission fluid pump. Hydraulic pressure is created in the transmission by the auxiliary transmission fluid pump. This would then allow the transmission to shift gears. If the motor driver would detect that the pump is not capable of producing the pressure as per the request, then this error code would start appearing.

What causes this problem with the Auxiliary Transmission Fluid Pump Control Circuit High?

• There can be inoperative electronic transmission fluid auxiliary pump
• There can be opened or shorted electronic transmission fluid auxiliary pump harness
• Quirks in the drive motor generator power inverter control module
• The transmission fluid pump control relay might be damaged

1. Transmission Fluid Pump Harness - Faulty pump harness can affect the performance directly and can cause erratic pump behavior with harsh shifts. Thus, replace faulty harness now!
2. 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.
3. Transmission Fluid Pump - A failed transmission fluid pump can cause the fluid not being able to circulate in the transmission and the driver may smell the fuel burning. Thus, it might need immediate replacement.
4. Powertrain Control Module - If the PCM is faulty, it can store 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. Automatic Transmission Module - Sometimes the transmission module is unable to communicate or correctly anticipate the speed of the vehicle and thus creates difficulty in gear shift leading to sluggish acceleration, throttle response and stalling. Thus, can also hamper a lot of components physically and thus must be checked and replaced, if required.
7. Diagnostic Tool - Choose from our diagnostic tools collection that will come in handy to detect and correct the OBD error code.

You might be thinking that how would you diagnose these problems? We at Parts Avatar Canada would help you diagnose the major symptoms easily.

Common Symptoms

• The service engine soon light can start lighting up
• Transmission might begin overheating
• There might be diminished shifting efficiency

The repairs which you will have to do to correct this fault code are simply straightforward; you can surely pinpoint the necessary repairs on the basis of your diagnosis. Have a look at some common fixes:

• Rehabilitate the defaults in the ECM/PCM
• The electronic transmission fluid auxiliary pump harness should be restored to working order
• Recondition the non-functioning transmission fluid pump control relay
• It is necessary to perform proper service of the unsound drive motor generator power inverter control module
• Adjust the flawed electronic transmission fluid auxiliary pump

There is no need to get strained if your OBD Code is still flashing up as we are here at your service. Have a look at our superior variety of automatic transmission fluid, torque converter, transmission solenoid, electronic pressure regulator, transmission shift solenoid, powertrain control module, multimeter, pcm, ecm, body control module component, powertrain control module, electronic control module, electronic transmission fluid auxiliary pump, electronic transmission fluid auxiliary pump harness, transmission fluid pump control relay, drive motor generator power inverter control module, transmission pump, pcm relay and many more. Now all your problems would vanish within no time.

Here are some steps which you should follow in order to diagnose this fault code:

There are some models which utilize an electronic auxiliary transmission fluid pump to help regulate transmission fluid pressure by raising the flow of fluid throughout the transmission, transmission cooler, and torque converter. There is an electronic controller which controls the pump by utilizing the system of wiring and relays. The powertrain control module would then utilize the input data from various transmission sensors to decide when the auxiliary transmission fluid pump must be turned on and turned off. CAN stands for “controller area network.” The CAN represents a communication bus that would allow a number of microcontrollers to communicate with one another without the need for a host computer. It is a message-based protocol initially designed for automotive use. The network of CAN bus is actually a complex conglomeration of wiring harnesses and connectors used as a pipeline of information which is shared between two or more automotive control modules. Every electrical function of the vehicle is virtually controlled by these controllers, with the powertrain control module being the primary controller. Control modules receive input data from various sensors and emit output signals to system constituents and other control modules. If this proves to be a CAN bus associated situation, then it could prove very challenging to diagnose by an amateur technician. Unlike other diagnostic codes, this type of code can sometimes be best left to a professional simply because of the bulk of circuitry involved. A technician which is experienced should use a specialized scanner (Autohex or Tech II) to determine the general area of the malfunction much more rapidly and easily than someone using a code reader as well as a digital volt ohmmeter. If you will disconnect and check every single pin of the CAN bus then it can consume a lot of time as well as money. Also make sure to install some type of memory saving device, test the PCM and other controllers lose their memory and sometimes they might require reprogramming. A specialized diagnostic CAN scanner will depict pin values and control module operation without risking a meltdown. It can diagnose computer and issues related to circuitry correctly by monitoring automobile operation while the vehicle is being operated. If you want to diagnose this type of code using a digital volt ohmmeter, then it would entail probing thousands of circuits separately.

One probe which is misplaced could destroy expensive control modules and require that the vehicle be totally reprogrammed. At the most, you may attempt to perform a continuity test after all control modules are disconnected, and this could literally require 40-hours or more, based upon the automobile. There are some applications are equipped with up to 18 separate control modules. If you choose to tackle this monumental task, then you must start with a careful visual inspection of all system circuitry, connectors, and fuses. Control module ground circuits should be inspected for continuity with battery ground. Generally, the faulty system grounds are reason behind the occurrence of these types of codes. An auxiliary ground cable can be supportive in diagnosing system ground discrepancies. Engine and transmission ground cables, straps, and wires are sometimes left dangling once the repairs have been made. Search for loose or corroded electrical connectors that might rise the circuit resistance and cause these types of codes to be stored. Obtain a CAN bus system wiring diagram and/or pin out value chart, then use the digital volt ohmmeter to test continuity between individual controller connectors. You must compare your findings with the manufacturer’s referenced values and repair open or shorted circuits as per the need. It is more economical to restore the faulty wiring rather than attempting to remove it from the complex web of wiring harnesses.

Common Mistakes When Diagnosing The P2799 Code

• There can be some faults in the drive motor generator power inverter control module
• Negligence in the auxiliary transmission pump
• Wiring problems