How to Replace an audi a5 key fob G28 Engine Speed Sensor

In this video, Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is located near the transmission's edge over the flywheel gear. It transmits a signal to the ECU via the grey wire (T55/49), then to the tachometer in the instrument cluster.

1. Engine Speed Sensor

The sensor is located at the edge of the transmission above the flywheel ring gear G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 using an uncolored wire. The ECU utilizes this information to regulate the amount of fuel and boost. It also sends a signal to the G5 tachometer in the instrument cluster.

The sensor is used to connect the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft is TDC and where the camshaft is so it can trigger spark and injectors in the right way.

If this sensor fails, the ECU will throw a P00160 code which means the Crank Shaft and Intake Camshaft aren't in sync and could indicate the chain stretching or a jump link on the upper timing chain. However the code will not be displayed on its own without additional information from other sensors (G4 and G40).

It's a bit tricky to test because there are different pins on the connector, and they all have different functions. The most effective method to test it is to measure the resistance between the ECU and the sensor. When the sensor is fully operational, it should read around 1000 ohms. Check for evidence of coolant or oil in the connector bay if you have problems with this part.

2. Injectors

Yesterday, while accelerating at full speed from the highway paytoll, I experienced massive power loss like the engine is out of gas or the injectors are not firing anymore. Today, i pulled out the spark plugs, 3 were soaked with gazoline and the 4th one was dry. When i crank the engine with no sparks, i place a tissue on the top of each of the injector holes and the 3 that were drenched in gazoline pop out, but the 4th stay closed. I tested the ground connection on ECU pins 14/55,30/55 and 48/55 i get zero ohm. So i assume the problem is elsewhere.

I also tried to reset the PID with no success. The car will start when the G28 is unplugged, and it works fine when the G28 plugged in. However the intermittent misfire issue persists at higher RPM. The coolant temperature sensor (G62) shows the wrong temperature value of -49c even when i unplug it. Also i noticed that the oil pressure gauge in the cockpit shows 2 bar when the actual pressure is 0.0 when i rev the engine.

I'm not certain what to do, as i feel i have pretty much completely ruled out all other possibilities. However, i'm afraid that I may have missed something. If anyone has suggestions, please chime in! TIA!

3. Fuel Pump

The fuel pump in the g28 receives signals from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. You can easily locate an extra in a wrecking shop or a parts store. Test them out 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 left on the black connector's end). They must be infinite ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY and ADU) engines are equipped with an ECU that needs to know the position and speed of the crankshaft to make decisions regarding timing of the fuel injectors, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you encounter a problem with either of these sensors, the diagnostic scanner will show codes that could lead to an engine shutdown.

A malfunctioning G28 sensor can cause an inaccurate speed counter for your gearbox, a gearbox that shifts faster than normal, or a misfire in the gear. It is possible that your sensor is failing and needs to be replaced if you encounter any of these symptoms. They are cheap and easy-to-find particularly if they're an Bosch unit like ours. Alternately, the GM version of this component is also a great option.

5. Tachometer

A damaged engine sensor could cause a myriad of issues in your car. It's an essential component of your Replacement audi a3 spare key a4 key (moiafazenda.ru)'s transmission, since it relays information to the ECU about how fast or slow the audi car key replacement cost's crankshaft is spinning. When this sensor fails, it can cause problems for Replacement Audi Key Fob the transmission as well as the rest of the car's components.

The G5 engine sensor is located at the edge of the transmission, just above the flywheel ring. It sends an electrical signal through gray wire to ECU pin T55/49. The ECU then processes this signal to regulate the flow of fuel, timig and boost as well as transmitting it to the G5 tachometer inside the instrument cluster. You can test the sensor for failure by checking continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. There should be the resistance to be around 1000 ohms between these points. This is a standard part that is found across the audi keyfob 80, 100 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU so good parts could be found in wrecking yards.