How to Replace an audi car key case G28 Engine Speed Sensor

Charles the Humble Technician teaches you how to replace the G28 Engine Speed Sensor. This sensor is located at the edge of transmission over the flywheel gear. It transmits a signal to the ECU via a grey wire (T55/49), then to the tachometer within 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 through an uncolored wire. The ECU then utilizes this information to regulate the flow of fuel, timig and boost. It also sends a signal to the G5 tachometer inside the instrument cluster.

The sensor serves as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must be aware when the crankshaft is TDC and the location of the camshaft so it can activate spark and injectors in the right way.

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

It is a little tricky to test because there are different pins on the connector, and each has its own functions. The most effective method to test it is by measuring the resistance between the ECU and the sensor. It should read about 1000 ohms when the sensor is at full operation. Examine for signs of coolant, or oil in the connector bay if there are problems with this part.

2. Injectors

Yesterday, Audi Tt Key Fob as i was accelerating off the highway paytoll at a high speed I noticed a massive drop 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 in gazoline, the fourth one was dry. When I start the engine, there are no sparks, i place a tissue on the top of each of the injector holes and the 3 drenched with gazoline leap out, however the 4th stays shut. I checked the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I got 0ohm. I think the issue is somewhere else.

I also tried to reset the PID with no success. The car will start when the G28 is disconnected, but it works fine when the G28 connected. However, the intermittent misfire problem persists at higher RPM. The coolant sensor (G62) even when unplugged, still shows temperatures of -49c. I also noticed that the oil gauge in the cockpit shows 2 bars but the actual pressure is zero.

I'm not sure what to do, but i think i've pretty much eliminated everything else. 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 gets a signal from the RPM sensor. The GM-style transmitter is similar to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. It is easy to find the spare in a salvage shop or a parts store. It is easy 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 up). 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. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you have a problem with either one of these, the diagnostic scanner will show codes that could cause the engine shutting down.

A malfunctioning G28 sensor could result in an inaccurate gearbox speed counter or a gearbox that shifts more quickly than normal, or a misfire while in the gear. If you experience any of these issues it is likely that your sensor is going bad and requires replacement. They're cheap and easy to find particularly when they're a Bosch model like ours. Alternately, the GM version of this part is also a good choice.

5. Tachometer

A malfunctioning engine sensor can cause a variety of issues in your vehicle. It's an essential component of the transmission of your Audi Tt Key Fob [Https://Telegra.Ph/The-Most-Common-Audi-Car-Key-Mistake-Every-Newbie-Makes-03-18] because it relays information to the ECU on how fast or slowly the engine is spinning. This sensor could cause the transmission to fail and other car components to be affected.

The G5 engine speed sensor is situated on the outside of the transmission above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49, via a grey wire. The ECU utilizes this signal to regulate fuel and boost, as well as timig. It also transmits it to the G5 Tachometer located in the instrument cluster. You can check the sensor for any failure by checking the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should see approximately 1000 ohms of resistance between these two points. This part is common across the Audi 80-100-200-RS2 range, 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.