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. The sensor is situated at the top of the transmission just above the flywheel ring gear. It transmits a signal to the ECU through the grey wire T55/49 and then to the tachometer on the instrument cluster.
1. Engine Speed Sensor
The grey wire is located on the edge of transmission, above the flywheel ring. This sensor sends signals through the grey wire to pin T55/49. The ECU uses this information to regulate boost and fuel. It also sends a signal to the G5 tachometer in the instrument cluster.
The sensor serves as a reference point to connect with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft is TDC and where the camshaft is located so that it can start spark and injectors according to the situation.
If this sensor fails to function, the ECU will display an error code P00160. This indicates that the Crank Shaft is out of alignment with the Intake Camshaft. It could also indicate an issue with the chain or a jump in the chain link of the upper timing chain. However, the code won't appear on its own without additional information from other sensors (G4 and G40).
Testing is a bit challenging since there are two connector pins, and they have different functions but the best way to test it is to measure resistance between the sensor and the ECU. It should read approximately 1000 ohms when it is operating at its maximum. If you're experiencing issues with this component, look for signs of oil or coolant in the connector bay.
2. Injectors
Yesterday, when i was accelerating to the fullest speed from highway paytoll, i experienced massive power loss like the engine is running out of gas or injectors are not firing anymore. Today, i pulled out the spark plugs, three were drenched in gazoline, the 4th one was dry. When I start the engine without sparks i put tissue on the top of each of the injector holes, the 3 drenched with gazoline jump out but the 4th stay shut. I tested the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ i get zero Ohm. I click here assume that the problem is in another location.
I also tried to reset the PID without success. The car will start when the G28 is disconnected, but it runs fine with the G28 connected. However, the intermittent misfire problem continues to occur at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature of -49c, even if I unplug it. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is zero.
I'm not sure what to do. I think I've all other possibilities out. But i am afraid I might have missed something. If anyone has any ideas please let me know! TIA!
3. Fuel Pump
The fuel pump of the g28 receives a signal from the RPM sensor. The GM-style transmitter is identical to the G4 and both are used in the 80 100 200, UrS and RS2 cars so you can easily find one at a salvage yard or at audi spare key a parts store. It is easy to test them - just switch your DMM into resistance mode and determine 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 have an ECU that needs to be aware of the speed and position of the crankshaft in order to make decisions regarding timing of the fuel injectors, etc. To do this, it uses a Crank Position Sensor (G4) click here and an Engine Speed Sensor (G28). If either of these sensors go wrong, you will receive codes on the diagnostic scanner that can cause the engine to shut down.
A malfunctioning G28 sensor can cause an inaccurate speed counter for your gearbox, a gearbox that shifts more quickly than normal, or a misfire while in gear. It is likely that the sensor is failing and needs to be replaced if you notice any of these signs. They're cheap and easy to find particularly in the case of a Bosch model like ours. Alternatively, the GM version of this part is also a great option.
5. Tachometer
A failing engine speed sensor could be the reason behind a slew of issues with your car. It's a vital component of the Audi's transmission because it communicates to the ECU about how fast or slow the car's crankshaft is turning. If this sensor fails, it will cause problems for the transmission and audi key programming near me the other car's components.
The G5 engine sensor is located at the outskirts of transmission, above the flywheel ring. It sends a signal via an uncolored wire to the ECU pin T55/49. The ECU uses this signal to control fuel and boost, and also to timigrate. It also transmits it to the G5 Tachometer inside the instrument cluster. You can check for sensor failure by checking continuity from the sensor to the tachometer. Also, you can examine the continuity between pins T55/49 of the ECU and audi a1 key replacement pin T6a/1 of the instrument cluster (trace [79trace [79]), and between pin T6a/1 as well as pin T26a/12. You should see the resistance to be around 1000 ohms between these two points. This is a common part that is found across the Audi 80 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU so good ones could be available in wrecking yards.