20 Myths About Audi G28: Debunked

How to Replace an Audi A1 Key Fob G28 Engine Speed Sensor

Charles the Humble Technician teaches you how to replace the G28 Engine Speed Sensor. This sensor is located on the outside of the transmission just above the flywheel gear. It sends a signal to the ECU via an uncolored wire (T55/49) and then to the tachometer located in the instrument cluster.

1. Engine Speed Sensor

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

The sensor is used to correlate with the G40 Camshaft position Sensor. The ecu must be aware when the crankshaft is TDC and where the camshaft is so it can activate spark and injectors according to the situation.

If this sensor fails, the ECU will show an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are not in sync, 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 can be a bit difficult to test since there are various pins on the connector and each one has different functions. The best method for doing this is by measuring the resistance between the ECU and the sensor. When the sensor is operational, it should read about 1000 ohms. Check for evidence of coolant or oil in the connector bay if you have issues with this component.

2. Injectors

Yesterday accelerating full speed from highway paytoll, I experienced an abrupt drop in power as if the engine was running out of gas or injectors aren't firing anymore. I pulled out the spark plugs this morning and found that 3 were drenched in gasoline and the 4th was dry. When I start the engine, there are no sparks i put tissue on the top of each of the injector holes, the 3 drenched with gazoline pop out, but the 4th one stays shut. I inspected the ground connection on ECU pins 14/55,30/55 and 48/55 I get zero Ohm. I'm assuming the issue is somewhere else.

I also tried to reset PID but without success. The car will start if the G28 is disconnected and it runs perfectly when it is connected however it has the intermittent misfire issue at higher RPM. The coolant sensor (G62) even if it is not plugged in, shows an ice temperature of -49c. Also, i noticed that the oil pressure gauge in the cockpit is showing 2 bar while the actual pressure is 0.0 when i rev the engine.

I'm not sure what to do, but i feel i have pretty much eliminated everything else. But i'm worried that I might have missed something. Let me know if you have any ideas! TIA!

3. Fuel Pump

The fuel pump in the g28 receives signals from the RPM sensor. The GM-style transmitter is identical to the G4 and they both work in the 80 100 200, UrS and RS2 cars so you can easily find one at a junkyard or at a parts store. Test them out - put your DMM in resistance mode and measure between pins 1 (with the bump on the connector's side up) and 2 (2nd from left on the black connector's side). 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 about timing of the fuel injectors, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you are experiencing issues with either of these, replacement audi a3 key (https://easiestbookmarks.com/story18248892/5-reasons-to-be-an-online-audi-a3-replacement-key-buyer-and-5-reasons-to-not) the diagnostic scanner will display codes that could cause an engine shut down.

Some of the symptoms of a failed G28 sensor are an inaccurate gearbox rev counter and gears that shift faster than normal and/or misfiring when you're in gear. It is probable that your sensor is failing and requires to be replaced if you experience any of these signs. They're inexpensive and easy to locate especially if they're an Bosch sensor like ours. Alternately, GM's version this part is an option.

5. Tachometer

A failing engine sensor could cause a myriad of issues within your vehicle. It is an important part of the transmission of your audi replacement key fob, as it transmits information to the ECU regarding how fast or slow the car's engine is spinning. If this sensor fails, it could affect the performance of the transmission and the rest of the car's components.

The G5 engine speed sensor is situated on the outside of the transmission just above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49 through an uncolored wire. The ECU is then able to process this signal to regulate fuel, timig and boost, and also transmitting it to the G5 tachometer inside the instrument cluster. You can determine if the sensor is in failure by checking continuity from the sensor to the tachometer. Additionally, you can verify continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]), and between pin T6a/1 as well as pin T26a/12. You should observe around 1000 ohms of resistance between these two points. This is a common feature across the audi key programming 80-100-200-RS2 range, Audi Tt Key Case from the 1985 MC all the way up to the 1997 UrS An and 1995 RS2 DU So, you may find good ones in wrecking yards.