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. This sensor is situated on the outside of the transmission over the flywheel gear. It sends a message 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. The sensor sends signals through the grey wire to pin T55/49. The ECU uses this information to control fuel and boost. It also sends an indicator to the G5 Tachometer within the instrument cluster.
The sensor is used to connect the G40 Camshaft position Sensor. The ecu has to be aware of when the crankshaft has reached TDC, and the location of the camshaft so that it can activate the spark and injectors.
If this sensor fails, the ECU will show the P00160 error, which means the Crank Shaft and Intake Camshaft are not in sync and possibly indicating the chain stretching or a jump link on the upper timing chain. However the code will not appear on its own, without additional information from other sensors (G4 and G40).
Testing is a bit tricky as there are two different connector pins and they perform different functions but the most effective method of testing it is by measuring resistance between the sensor and the ECU. When the sensor is functional, it should read approximately 1000 ohms. If you're experiencing issues with this part, check for signs of coolant or oil in the connector bay.
2. Injectors
Yesterday accelerating full speed from highway paytoll i had massive power loss as if the engine was running out of gas or the injectors are not firing anymore. Today, i pulled out the spark plugs, three were drenched with gazoline the fourth was dry. I put tissue over each injector hole and when I start the engine with no sparks, the ones with gazoline jump right out. The 4th one remains shut. I inspected the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ i get zero Ohm. I'm assuming that the issue is elsewhere.
I also tried to reset the PID but with no luck. The car can start when the G28 is unplugged and it runs perfectly when it is connected, but still is experiencing intermittent misfires at higher RPM. The coolant sensor (G62) even if it is not plugged in, shows temperatures of -49c. I also noticed that the oil gauge in the cockpit shows 2 bars when the actual pressure get more info is zero.
I'm not certain what to do, but i believe that i've completely ruled out all other possibilities. I'm concerned that i may have missed something. Let me know If you have any suggestions! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal sent by the RPM sensor. The GM-style transmitter is identical to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. You can easily find an extra in a wrecking shop or a parts store. Testing them is easy to do - just put your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector end up) and 2 (2nd from the left on the black end of the connector). They must be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY, and ADU) engines are equipped with an ECU that has to know the position and speed of the crankshaft in order to make decisions regarding timing of the fuel injector, for example. To accomplish this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you are experiencing issues with either of these sensors, the diagnostic scanner will display the codes that could trigger an engine shut down.
A failing G28 sensor could cause an inaccurate speed counter for the gearbox, a gearbox that shifts more quickly than normal, and/or a misfire in gear. If you are experiencing any of these issues it is likely your sensor is going bad and needs replacing. The good news click here is that they are very affordable and easy to find particularly if you're looking at the Bosch sensor, which is what we have. Alternatively, the GM version of this unit is also a good choice.
5. Tachometer
A faulty engine get more info speed sensor could be the reason behind a slew of problems in your vehicle. It's a vital component of your Audi's transmission, as it sends information to the ECU about how fast or slow the vehicle's crankshaft is turning. If this sensor fails, it can cause problems for the transmission as well as the other car's components.
The G5 engine sensor is located at the outskirts of transmission, above the flywheel ring. It transmits a signal via an uncolored wire to the ECU pin T55/49. The ECU uses this signal to regulate fuel and boost, and also to timigrate. It also relays it to the G5 Tachometer in instrument cluster. You can check for sensor failure by examining the continuity of the sensor to the tachometer. Additionally, you can verify continuity between pin T55/49 of the ECU and pin click here T6a/1 of the instrument cluster (trace [79trace [79]) and between pin T6a/1 and pin T26a/12. You should detect the resistance to be around 1000 ohms between these points. This part is common across the Audi 80-100-200-RS2 series, starting from the 1985 MC all the way up to the 1997 UrS AN and here the 1995 RS2 Du You may also find some good ones in wrecking yards.