Why Nobody Cares About Audi G28

How to Replace an audi tt key fob not working G28 Engine Speed Sensor

Charles the Humble Technician teaches 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 a grey wire (T55/49), then to the tachometer within the instrument cluster.

1. Engine Speed Sensor

It is located on the outside of the transmission, above the flywheel ring gear, the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 through a grey wire. The ECU uses this information to regulate fuel and boost. It also sends an alert to the G5 Tachometer within the instrument cluster.

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

If this sensor fails the ECU will throw an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are not in sync and possibly indicating the chain is stretched or a jump link on the upper timing chain. The code will not appear without the additional information supplied by other sensors (G4 or G40).

Testing is a bit challenging since there are two pins for the connector and they perform different functions but the most effective method of testing it is to measure resistance between the sensor and the ECU. It should read around 1000 ohms when it is operating at its maximum. Look for signs of coolant or oil in the connector bay if you are experiencing problems with this part.

2. Injectors

Yesterday, while accelerating at full speed from the highway paytoll, i experienced massive power loss as if the engine was running out of gas or injectors aren't firing at all. I took out the spark plugs this morning and found that 3 were drenched in gasoline and the 4th was dry. I put a piece of tissue over each injector hole and when i start the engine with no sparks, the 3 that have gazoline pop right out. The 4th one remains shut. I checked the ground connection of ECU pins 14,30, and 48/55. I got zero ohm. I'm assuming the issue is elsewhere.

I also tried to reset the PID but without success. The car will start if the G28 is unplugged and runs fine when it is plugged in, but still has intermittent misfire issues at higher RPM. The coolant sensor (G62), even if it is not plugged in, shows temperatures of -49c. Also i noticed that the gauge for oil pressure in the cockpit shows 2 bar when the actual pressure is 0.0 if i crank up the engine.

I'm not certain what to do, but i believe that i've completely ruled out all other possibilities. I'm concerned that i may have missed something. Please 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 sender is identical to the G4 and they both work in the 80, 100, 200, UrS and RS2 cars which is why you can easily locate one at a salvage yard or from a parts store. Testing them is easy - put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector end up) and 2 (2nd from the left on the black connector's side). They should be infinite Ohms.

4. ECU

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

A failing G28 sensor could cause an inaccurate gearbox speed counter and a gearbox which shifts more quickly than normal, or a misfire while in gear. It is likely that your sensor is failing and requires to be replaced if you experience any of these symptoms. They're cheap and easy to find especially when they're an Bosch model like ours. If you prefer, GM's version of this part is an excellent choice.

5. Tachometer

A faulty engine speed sensor could be the reason behind a slew of issues in your car. It's an essential component of your Audi's transmission, since it relays information to the ECU about how fast or slow the car's crankshaft is turning. When this sensor fails, it could cause problems for the transmission, as well as the other car's components.

The G5 engine speed sensor is situated on the edge of the transmission above the flywheel ring gear. It sends a signal to the ECU at pin T55/49, via an uncolored wire. The ECU utilizes this signal to regulate the flow of fuel and boost as well as timig. It also sends it to the G5 Tachometer inside the instrument cluster. You can determine if the sensor is in failure by examining the continuity from the sensor to the tachometer. Also, you can verify continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]) and between pin T6a/1 and pin T26a/12. It should show around 1000 ohms of resistance between those two pins. This is a common feature 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, audi keys replacement audi key cost uk (https://g2847115.kylieblog.com/30291053/what-Experts-on-audi-a3-key-replacement-want-you-to-know) so you might find some good ones in wrecking yards.