VW Polo 9N Mk4 AZQ engine speed sensor G28 crankshaft position sensor fixed.
Watch the video first
Bad Crankshaft Engine Speed Sensor G28 Symptoms
Even while driving on the motorway engine shuts off.
Imagine driving at 100km/h and suddenly the engine turns off while driving and power steering stops working the brakes servo assist stops working.
What to do when the engine stops while driving
If that happens, turn your hazard emergency lights on and slowly and predictable pull towards the emergency lane.
Do not stop the car on the highway or motorway lanes but pull left or right depending on your country’s driving side.
The steering wheel is much harder to turn when the engine is off and the brakes are almost not working.
Even with steering wheel servo not working, you can rotate the steering wheel slowly until you are on the emergency lane.
Because the engine is off, the car is slowing down and you might not need to press the brakes or press the brakes slightly to reduce speed sooner if you are close to an motorway exit, you want to stay out of the way of other cars.
Other G28 sensor failure symptoms
Some ways the G28 engine speed sensor might fail is by slight engine stuttering when you press the gas pedal from idle. You feel something is worng with the car. Acceleration is not smooth anymore.
If the engine speed sensor failed completely, the car engine won’t start or might start run for a second then turn off.
What does the Engine Crankshaft Position Sensor do
The G28 crankshaft position sensor is a hall effect magnetic sensor that together with the engine flywheel with teeth will detect the engine speed and send the speed of the engine pulses to the car ECU. This information is crucial to adjust the engine timing of how each cylinder fuel injector is firing and for how to spark plugs work.
Safety is the reason
The engine stops for safety as incorrect G28 makes the ECU think, the engine is stalled or something very bad happened with the engine. It shuts off the engine to prevent engine damage or car damage.
How to fix it
Vw Polo engine speed sensor crankshaft position sensor was failing.
Engine shutters or hesitates when pressing the gas pedal.
Easy DIY to replace the sensor if you have the same problems.
When I was searching the net for this it was very hard to find a video like this .. so .. here it is for you as a video and article with photos and step-by-step diy article guide.
In the video you can see the symptoms of a bad engine speed sensor or when the engine speed sensor is starting to fail with intermittent errors.
Confirm engine speed sensor fault
To confirm the crankshaft position sensor fault read the engine speed using VCDS VAG-COM to log engine rpm and then open the engine RPM speed log file in Excel or any spreadsheet app like Google Sheets or Open Office.
How to find the location of the G28 sensor
To locate the engine speed sensor G28, you first find the place where the engine meets the gearbox.
Under the engine, closer to the back of the engine block. Under the throttle body as seen in the video.
How to replace the G28 engine crankshaft position sensor
To replace the G28 engine crankshaft position sensor you have to carefully disconnect the electrical connector using a screwdriver to release the locking tab but be careful NOT to break the connector tab.
Remove the electrical connector by wiggling it left and right or you might even spray WD-40 on the electrical connector housing to make it come out easier.
There is one screw holding the engine crankshaft sensor in place.
Can’t remember the screw bit size but you should have a Torx socket set and try a few torkx bits until you find the right one.
There may be dirt in the screw hole and the torx bit may not lock in all the way. Spray WD-40 and use a small wire or needle to pull any crusty dust out then try again.
Pull out old G28 sensor
Once the screw and connector are disconnected, pull the G28sensor out by wiggling the sensor body sliglty. Patience is key here!
Sensor will come out as seen bellow.
Install new G28 sensor
Install the new G28 sensor as you saw it coming out. It has a specific way it goes in and when fully inserted it must allgn with the scre hole and be flush with the engine block.
Reinstall the torx screw and install the electrical connector making sure you feel or hear it clicking when fully inserted. You can clean the connector with WD-40 2 or 3 sprays and wipe it well before installing. WD-40 makes the connector slide easier on the sensor body.
Once they connector clicks, try to pull it a bit to make sure it’s secured in place.
Remove any tools you might have around the car and try to start the car. If the car starts and idles well, try to drive around on an empty street and see if the engine stutters or the engine shuts off. If all is ok, you fixed it congratulations!
Write a comment bellow on how it was for you so other readers can find out.