Error Code P258A: What It Means & What To Do?

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Is the vehicle’s climate control system not working properly? Do you notice Check Engine Light illumination on the dashboard? These are the indication towards faulty vacuum pump control circuit causing OBD code P258A getting stored in the system.

Vacuum pump is a device which gets the drive from engine camshaft. In some designs, it is driven by the alternator shaft. The main function of vacuum pump is to evacuate the air from the brake booster tank, thus creating vacuum, which can be used for brake application. In addition to this, in new generation engines, to meet the desired emission targets, vacuum pump also has to create vacuum in the auxiliary tank which will be used to actuate the turbocharger wastegate actuation mechanism and EGR valve.

Thus, when the vacuum pump control circuit gets faulty, OBD code P258A gets stored in the powertrain control module (PCM).

What causes this problem with the Vacuum Pump Control Circuit/Open?

• Vacuum pump control circuit open
• Relay control circuit open/high resistance
• Electric vacuum pump (EVP) relay damaged
• Powertrain Control Module (PCM) failure

1. Engine Control Module - There can be some engine performance issues due to faulty engine control module. If the ECM fails or has any problems it can lead to performance issues with the vehicle like misfires, hesitation, loss of power, and sometimes even decreased fuel economy.
2. Powertrain Control Module - PCM stands for powertrain control module. It is a car part, a control unit which is utilized on motor vehicles. It is generally a combined control unit, consisting of the engine control unit (ECU) and the transmission control unit (TCU).
3. Electronic Control Unit - If your automobile's check engine light remains on constantly, and never goes off, there's a good chance that your vehicle has a damaged electronic control unit. There are a lot of reasons why a car's check engine light will remain on. The most common reason is a defective ECU.
4. Diagnostic Tools - It is always advisable to use correct tools and equipment while resolving any OBD code issue as even small mistakes can lead to wrong diagnosis. Thus, always take help from a professional who has the knowledge and experience to such tools in efficient manner. Buy new quality diagnostic tools from us today!
5. Vacuum Pump - If the vacuum pump is faulty, it will lead to problem in the climate control system and the vehicle brakes controls. This can also lead to delayed response from the brake pedal. Thus, replace it now!
6. Vacuum Pump Repair Kit - When a vacuum leak exists, it is most commonly caused by vacuum hoses that are broken, have faulty connections or the vacuum pump is not in operation. If you listen very carefully, sometimes you can hear a "hiss" sound that is the signal of a vacuum leak. However, the most common way to notice this is when the engine loses fuel efficiency. The reason for this is due to the fact that vehicle exhaust is delayed on exiting the combustion chamber. Thus, do the repairs properly.
7. Vacuum Pump Belt - When there is a build-up of burnt fuel, the new fuel burns less efficiency. This condition will also reduce engine performance; but it really depends on the manufacture and use of the vacuum pump. If you notice that you have poor fuel efficiency – in both gasoline and diesel engines, take help of local certified mechanic and inspect your vacuum pump, hoses, and engine for any vacuum leaks. Replace the faulty vacuum pump belt immediately.

Interested in knowing the symptoms to OBD code P258A? If yes, then you have arrived at the right place. We at Parts Avatar have listed out few common symptoms associated with Vacuum Pump Control Circuit/Open.

Common Symptoms

• Poor fuel efficiency
• Check engine light on
• Brake pedal hard to press
• Leaking oil under the side of the engine
• Air conditioning not working

Have a look at some ways with which you can correct the P258A code:

• Vacuum pump replacement
• Vacuum pump belt and hoses replacement
• Faulty wiring and connector replacement
• Powertrain control module repair, replace and reprogramming

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 Electric Vacuum Pump, Vacuum Pump Relay, Powertrain Control Module 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 P258A fault code:

• The first step is to complete a visual inspection of the wiring for the vacuum pump control circuit.
• Many times, this code can be set due to damaged wirings which are wrongly routed or damaged by road hazards.
• Check for the stored OBD code and freeze frame the data. Test drive the car to see if the code reappears and compare it with stored data to confirm the error code presence.
• Next, turn off the ignition and remove the EVP relay from the relay connector. Then, turn the ignition on and use a 12-volt test light connected to ground, probe the fused ignition RUN/START circuit (terminal 85) at the EVP relay connector.
• Measure the resistance of the EVP relay coil for terminal 85 and 86 by turning the ignition off.
• Next, EVP relay connector and the PCM harness connector resistance must be measured. Note that the PCM connector must be disconnected.
• At the EVP relay socket, check for continuity between ground and the Vacuum Pump relay control circuit.
• Replace all the faulty components if the readings are not in the specific parameters.

Common Mistakes When Diagnosing the P258A Code

• EVP relay failure
• Vacuum pump failure
• Vacuum pump circuit wiring and connector issue
• PCM faults and errors