How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. The sensor is located on the edge of the transmission, above the flywheel ring gear. It transmits a signal the ECU via the grey wire (T55/49) which is then sent to the tachometer located in the instrument cluster.
1. Engine Speed Sensor
The grey wire is situated on the edge of transmission, directly above the flywheel ring. The sensor transmits a signal via the grey wire to pin T55/49. The ECU utilizes this information to control boost and fuel. It also sends signals to the G5 tachometer in the instrument cluster.
The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu must be aware of when the crankshaft has reached TDC and also where the camshaft lies in order to activate the spark and injectors.
If this sensor fails to function, the ECU will display a P00160 error message. This indicates that the Crank Shaft is not in line with the Intake Camshaft. It could also indicate a chain stretch or a jump in the chain link of the upper chain of timing. The code won't appear without the additional information supplied by other sensors (G4 or G40).
Testing can be a bit difficult because there are two pins for the connector and they perform different functions but the most effective method of testing it is to measure the resistance between the sensor and the ECU. When the sensor is operational, it should be reading around 1000 ohms. Check for signs of coolant or oil in the connector bay if you have issues with this component.
2. Injectors
Yesterday, while accelerating at full speed from the highway paytoll, I experienced an abrupt drop in power like the engine is running out of gas or the injectors are not firing anymore. In the morning, i removed the spark plugs, three were drenched in gazoline, the 4th one was dry. When i crank the engine, there are no sparks, i place a tissue on top of each injector hole and the 3 that were drenched in gazoline jump out but the 4th stays closed. I checked the ground connection on ECU pins 14/55,30/55 and 48/55 I get zero Ohm. I'm assuming that the issue is in another location.
I also tried to reset the PID but with no luck. The car will start if the G28 is disconnected and it runs perfectly when it is plugged in however it is experiencing intermittent misfires at higher RPM. click through the next document (G62), even when unplugged, still shows temperatures of -49c. how much is a replacement audi key noticed that the oil gauge in the cockpit shows 2 bar while the actual pressure is zero.
I'm not sure what to do, as i believe that i've eliminated everything else. I'm afraid i may have missed something. If anyone has any suggestions, please let me know! TIA!
3. Fuel Pump
The fuel pump in the g28 gets a signal from the RPM sensor. The GM-style sensor is identical to the G4 and both function in the 80 100, 200, UrS and RS2 cars which is why you can easily locate one at a wrecking yard or from a parts store. It is easy to test them: simply put your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump on the connector's edge 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 be aware of the speed and position of the crankshaft to make decisions regarding timing of the fuel injector, for example. In order to do this it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these go badly, you will see codes on the diagnostic scanner which can lead to engine shutdown.
Some of the signs of a failing G28 sensor are an inaccurate rev counter for the gearbox and gears that shift faster than normal and/or misfiring when in gear. It is probable that the sensor is failing and requires to be replaced if you notice any of these signs. The good news is they are very cheap and easy to find, especially when you're looking at the Bosch model, like ours. Alternatively, GM's version of this part is an excellent choice.
5. Tachometer
A malfunctioning engine speed sensor could be the reason behind many problems in your vehicle. It's a crucial component of the transmission in your Audi because it relays information to the ECU regarding how fast or slowly the engine of the car is turning. If this sensor fails, it could disrupt the performance of the transmission as well as the rest of the car's components.
The G5 engine sensor is located near the edge of the transmission, just above the flywheel ring. It transmits an electrical signal through gray wire to ECU pin T55/49. The ECU utilizes this signal to regulate the flow of fuel and boost and also timig. It also sends it to the G5 Tachometer in instrument cluster. You can check the sensor for failure by examining the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should see the resistance to be around 1000 ohms between these points. This is the same across the Audi 80-100-200-RS2 model, ranging beginning with the 1985 MC and up to the 1997 UrS An and 1995 RS2 Du So, you may find good ones in wrecking yards.