How to Replace an audi Key shell G28 Engine Speed Sensor

In this video Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. The sensor is situated at the top of the transmission, above the flywheel ring gear. It sends a message to the ECU via a grey wire T55/49, then to the tachometer on 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 signals to ECU pin T55/49 via the grey wire. The ECU uses this information to control fuel and boost. It also sends a signal to the G5 tachometer inside the instrument cluster.

The sensor is used to correlate with the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft is TDC and the location of the camshaft so it can trigger spark and injectors accordingly.

If this sensor fails when it fails, the ECU will display an error code P00160. This means that the Crank Shaft is not in alignment with the Intake Camshaft. It could also indicate an issue with the chain or a jumped chain link in the upper chain of timing. However, the code won't appear on its own without additional information from other sensors (G4 and G40).

Testing can be a bit difficult as there are two different connector pins, and they serve different purposes however the best method of testing it is to measure resistance between the sensor and the ECU. It should read about 1000 ohms when the sensor is operating at its maximum. Examine for signs of coolant or oil in the connector bay if there are issues with this part.

2. Injectors

Yesterday, when accelerating from highway paytoll at a high speed, i noticed a huge reduction in power. It was as if the engine had run out of gas. Or my injectors were not firing. Today, i pulled out the spark plugs, three were drenched with gazoline the 4th one was dry. When i crank the engine without sparks, I put a piece of tissue on the top of each hole in the injector, the 3 drenched with gazoline pop out, but the 4th one stays shut. 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 in another place.

I also tried to reset PID but without success. The car will start when the G28 is unplugged, and it works fine when the G28 plugged in. However, the intermittent misfire problem still occurs at higher RPM. The coolant sensor (G62) even when unplugged, still shows a temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is zero.

I don't know what to do. I believe that I've eliminated everything else. 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 in the g28 is activated by a signal from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender and works on the 80,100,200, UrS, Audi a3 Keys and reprogram RS2 vehicles. You can easily find the spare in a salvage shop or a parts store. It is simple to test them - simply switch your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector end facing upwards). They must be infinite ohms.

4. ECU

The ECU of our 20vt turbo (3B AAN ABY) engines needs to know the position and speed of the crankshaft to determine timing of the fuel injector, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If either of these goes bad you will get codes on the diagnostic scanner which can lead to engine shutdown.

A malfunctioning G28 sensor can cause an inaccurate speed counter for Replacement audi a3 key the gearbox or a gearbox that shifts more quickly than normal, and/or an unfire when in gear. It is possible that your sensor is failing and requires to be replaced if you notice any of these signs. They're cheap and easy to find especially if they're a Bosch model like ours. Alternately, GM's version this component is an option.

5. Tachometer

A malfunctioning engine speed sensor could be a cause for many issues in your car. It is a crucial part of your audi tt key case's transmission, since it relays information to the ECU about how fast or slow the vehicle's crankshaft is rotating. This sensor can cause the transmission to fail and other components of the car to be affected.

The G5 engine speed sensor is located at the outside of the transmission, above the flywheel ring gear. It transmits a signal to the ECU at pin T55/49 via an uncolored wire. The ECU uses this signal to regulate the amount of fuel and boost, and also timig. It also sends it to the G5 Tachometer in 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 via pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should see an average resistance of 1000 ohms between these points. This is a common component across the audi car key holder 80 100 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU, so the best parts could be found in wrecking yards.