Notes

20 Trailblazers Are Leading The Way In Audi G28
How to Replace an Audi G28 Engine Speed Sensor

Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. This sensor is located at the top of the transmission, above the flywheel ring gear. It transmits a signal to the ECU through the grey wire T55/49 and then to the tachometer in the instrument cluster.

1. Engine Speed Sensor

Located on the edge of the transmission above the flywheel ring gear G28 Engine Speed Sensor sends a signal to ECU pin T55/49 using an uncolored wire. The ECU uses this information to regulate fuel and boost. It also sends signals to the G5 tachometer in the instrument cluster.


The sensor serves as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft reached TDC, and the position of the camshaft, in order to activate the spark and injectors.

If this sensor fails, the ECU will show the P00160 error, which means the Crank Shaft and Intake Camshaft aren't in sync and possibly indicating the chain is stretched 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).

It's a bit tricky to test because there are various connector pins, and each one has different functions. The best way to do it is by measuring the resistance between the ECU and the sensor. It should read about 1000 ohms when the sensor is operating at its maximum. If you are having problems with this sensor, look for evidence of coolant or oil in the connector bay.

2. Injectors

Yesterday, as i was accelerating off the highway paytoll at maximum speed, i noticed a huge drop in power. It was as if the engine had run out of gas. Or, my injectors weren't firing. This morning i pull out the spark plugs, three were soaked with gazoline and the fourth one was dry. When I start the engine with no sparks, I put a piece of tissue on the top of each of the injector holes and the 3 that were drenched in gazoline leap out, however the 4th stays closed. I tested the ground connection on ECU pins 14/55, 30/55 and 48/55. I get zero ohm. I think the issue is somewhere else.

I also tried to reset PID without success. The car is able to start when the G28 is unplugged and is running fine when it is connected, but still has the intermittent misfire issue at higher RPM. The coolant sensor (G62) even when it is unplugged, shows an ice temperature of -49c. Also i noticed that the oil pressure gauge in the cockpit is showing 2 bar when the actual pressure is 0.0 when i rev the engine.

replace audi key don't know what to do. I think I've all other possibilities out. But i'm worried that I may have missed something. Let me know If you have any suggestions! TIA!

3. Fuel Pump

The fuel pump in the g28 receives signals from the RPM sensor. The GM-style sensor is the same as the G4 and both function in the 80 100 200, UrS and RS2 cars so you can easily find one at a salvage yard or in a local parts store. It is simple to test them - put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's side up) and 2 (2nd from left on the black end of the connector). new audi car key must be infinite Ohms.

4. ECU

The ECU of our 20vt turbo (3B AAN ABY) engines needs to know the position and speed the crankshaft to make decisions regarding timing of fuel injectors, etc. To do 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 codes that could cause an engine shutdown.

A failing G28 sensor could cause an inaccurate gearbox speed counter, a gearbox that shifts more quickly than normal, or an unfire when in gear. If you experience any of these issues it is likely that your sensor is failing and should be replaced. They are cheap and easy-to-find, especially in the case of an Bosch sensor like ours. You can also choose the GM version of this part is also a great option.

5. Tachometer

A malfunctioning engine sensor can cause a number of problems in your car. It's a crucial component of the transmission of your Audi because it relays information to the ECU regarding how fast or slow the car's engine is turning. When this sensor fails, it could cause problems for the transmission and the other car's components.

The G5 engine speed sensor is located at the outside of the transmission just above the flywheel ring gear. It sends a signal to the ECU at pin T55/49, via a grey wire. The ECU uses this signal to control the flow of fuel and boost and also timig. It also relays it to the G5 Tachometer located in the instrument cluster. You can check the sensor for failure by checking continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should observe approximately 1000 ohms resistance between those two pins. This part is common across the Audi 80-100-200-RS2 model, ranging from the 1985 MC up to the 1997 UrS An and 1995 RS2 Du So, you may find some good ones in wrecking yards.

Here's my website: https://output.jsbin.com/dobemunoku/