How to Replace an Audi G28 Engine Speed Sensor
In this video Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. genuine audi key replacement is located on the outside of the transmission, above the flywheel gear. It sends a message to the ECU via an uncolored wire T55/49, then to the tachometer on the instrument cluster.
1. Engine Speed Sensor
The sensor is located at the edge of the transmission above the flywheel ring gear, the G28 Engine Speed Sensor sends signals to ECU pin T55/49 using a grey wire. The ECU uses this information to regulate boost and fuel. It also sends an alert to the G5 Tachometer in instrument cluster.
The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu must be aware when the crankshaft is TDC and where the camshaft is located so that it can activate spark and injectors in the right way.
If this sensor fails the ECU will throw an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are not in sync and possibly indicating the chain is stretched or a jump link on the upper chain of timing. However, the error code won't appear on its own without additional information from other sensors (G4 and G40).
Testing is a bit challenging as there are two different connector pins and they have different functions but the most effective way to test it is to measure the resistance between the sensor and the ECU. When the sensor is fully operational, it should read about 1000 ohms. If you're having issues with this part, check for evidence of oil or coolant in the connector bay.
2. Injectors
Yesterday, when accelerating from highway paytoll at full speed I noticed a massive decrease in power. It was like the engine had run out of gas. Or my injectors weren't firing. Today, i pulled out the spark plugs. Three were drenched in gazoline, the 4th one was dry. I put a piece of tissue over each hole in the injector and when I start the engine with no sparks, the 3 that have gazoline pop right out. The 4th one remains shut. I checked the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I got zero Ohm. I think the issue is in another location.
I also tried to reset the PID but with no luck. The car is able to start if the G28 is unplugged and it runs perfectly when it is connected however it is experiencing intermittent misfires at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temp value -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows 2 bars while the actual pressure is zero.
I'm not certain what to do, as i believe that i've ruled out everything else. But i'm worried that i might have missed something. If anyone has any suggestions, please share them! TIA!
3. Fuel Pump
The fuel pump on the g28 is activated by a signal sent by the RPM sensor. The GM-style transmitter is similar to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. You can easily locate a spare in a wrecking shop or parts store. It is easy to test them - just put your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector's end facing upwards). They should be infinite ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY, and ADU) engines are equipped with an ECU that needs to know the speed and position of the crankshaft in order to make decisions about fuel injector timing etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these goes badly, you will see codes on the diagnostic scanner that can cause the engine to shut down.
The signs of a failing G28 sensor include an inaccurate gearbox rev counter, gears shifting quicker than normal and/or a misfire when you are in gear. If genuine audi key replacement are experiencing any of these problems, it is most likely that your sensor is going bad and needs replacing. They are cheap and easy-to-find especially in the case of a Bosch unit like ours. You can also choose the GM version of this component is also a good choice.
5. Tachometer
A failing engine sensor could cause a number of problems within your vehicle. It's a crucial component of the transmission of your Audi because it relays information to the ECU regarding how fast or slowly the car's engine is turning. This sensor can cause the transmission to fail and other components in the car to be affected.
The G5 engine sensor is located at the edge of the transmission, just above the flywheel ring. It sends signals via gray wire to ECU pin T55/49. The ECU is then able to process this signal to regulate fuel, timig and boost and then transmitting it to the G5 tachometer in the instrument cluster. You can check the sensor for any failure by checking the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. There should be an average resistance of 1000 ohms in these areas. This part is common across the Audi 80-100-200-RS2 series, starting from the 1985 MC up to the 1997 UrS AN and 1995 RS2 Du You may also find good ones in wrecking yards.
