P3978 Engine Trouble Code

When you check engine light came on code P3978 the reason should be . However your vehicle's manufacturer may have a different definition for the P3978 OBD-II Diagnostic Powertrain (P) Trouble Code. So you should chech it on our car models.

When the DTC check engine light comes P3978 code on the first you can check is the gas related maybe gas cap. Pull over, retighten it, and take a look at the cap to see if it has any cracks inside. Go on driving and to see if the check engine light turns off automaticly. On the other hand, you can buy a gas cap for about $4.5 at an auto parts store. All you need to do is take the old one take off and take on the new one. If you've already bought it to the store, you might as well just replace the cap. While not car-threatening, it's good to take care of this right away to improve gas mileage/km.

P3978 Code Meaning :

The oxygen (02) sensors on your car measure the oxygen in the exhaust to determine how rich or lean the ratio of fuel and air are in the cylinders. Optimizing this mixture means better fuel economy and fewer exhaust emissions.

P3978 OBD-II Diagnostic Powertrain (P) Trouble Code Description

P3978 engine trouble code is about Timing Reference High Resolution Signal A Too Many Pulses. Fuel Rail/System Pressure - Too High and Injection lump Fuel Metering Control 'B' High (Cam/Rotor/Injector) causes most of code P3978.

Reason For P3978 Code

P3978 code on vehicles with electronically controlled automatic transmissions, the 3-4 shift solenoid is responsible for actuating the hydraulic circuits to activate clutches or bands that change gears inside the automatic transmission in your car.

How To Repair P3978 Code

Before starting let's see P3978 repairing process steps:

• Qualified technicians will begin by using a scan tool to access P3978 code stored in the ECU.
• Technicians will note P3978 code present and any freeze frame data associated with them.
• After all, if you sure the engine trouble is finished, the code will be cleared.

The fluid pressure sensor provides the PCM with the data necessary to monitor the transmission performance. If the fluid pressure increases, the electrical voltage reading from the pressure sensor will increase; if the pressure decreases, the voltage decreases.

This process helps the mechanic narrow down the exact cause of the issue. If the transmission fluid fix did not cause the code to disappear from the PCM, then next step is to inspect the electrical components, and to continue working through possible repairs until the correct issue is found.

Diagnosis Of Engine Error OBD Code P3978

It's essential to diagnose this trouble code. Then are some way which a handyperson should follow for diagnosing the problem that started a P3978 trouble code to be stored

The first step is introductory and is about reacquiring all the canons that have been set. For this, the individual scanner will have to be plugged into the individual harborage of your vehicle. Make sure you indurate frame the data. Any canons that were set previous to the P3978 code will have to be sorted first, as they may have been the reason for the law to set in the first place. It's always good to rule that out.

The coming step is to run a introductory examination of all the electrical circuits, connectors, wiring etc for damages similar as becks, erosion, fraudulent legs etc. All of these will have to be repaired or replaced. After that's sorted, clear the canons and go on a test drive to see if it resets. In case it resets, you'll have to continue your opinion. Depending on your vehicle you may have a vacuum operated selector or a vacuum solenoid if it's electrically actuated. In the case of the former, a hand held vacuum pump will have to be used to testit.The purpose is to see if the internal stopcock is getting turned by the selector, motor or solenoid. In order to do this, a command can be transferred to the system with scanner or by driving the vehicle under the special conditions that will spark the system. While this is passing keep an eye on the checkup tool data for the result.