A Look At The Ugly Facts About Audi G28

How to Replace an audi a3 key fob replacement G28 Engine Speed Sensor

Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. The sensor is located near the edges of the transmission, above the flywheel ring gear. It transmits a signal to the ECU via the grey wire (T55/49), then to the tachometer within the instrument cluster.

1. Engine Speed Sensor

The grey wire is located on the outside of the transmission, just above the flywheel ring. The sensor transmits an electrical signal through the grey wire to pin T55/49. The ECU then utilizes this information to regulate the boost, fuel, and timig. It also sends an indication to the G5 Tachometer located in the instrument cluster.

The sensor serves as a reference to correlate with the G40 Camshaft Position Sensor. The ecu has to be aware of when the crankshaft has reached TDC and also where the camshaft lies so that it can activate the spark and injectors.

If this sensor fails, the ECU will display a P00160 code which means the Crank Shaft and Intake Camshaft aren't in sync, possibly indicating chain stretch or a jumped link on the upper timing chain. The code won't show without the additional information supplied by other sensors (G4 or G40).

Testing can be a bit difficult as there are two different connector pins and they have different functions however the best method of testing it is to measure resistance between the sensor and the ECU. If the sensor is functional, it should read approximately 1000 ohms. If you're having issues with this sensor, look for evidence of oil or coolant in the connector bay.

2. Injectors

Yesterday, while accelerating from the highway paytoll at a high speed, i noticed a huge drop in power. It was like the engine had run out of gas. Or my injectors weren't firing. I took out the spark plugs this morning, three were soaked in gasoline, and the fourth was unclean. When i crank the engine, there are no sparks, I put a piece of tissue on top of each injector hole, the 3 drenched with gazoline leap out, however the 4th stay shut. I checked the ground connection of ECU pins 14,30 and 48/55. I found 0ohm. I think the issue is elsewhere.

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

I'm not sure what to do. I believe that I've all other possibilities out. However, i'm afraid that I might have missed something. Let me know if you have any ideas! TIA!

3. Fuel Pump

The fuel pump of the g28 gets a signal from the RPM sensor. The GM-style transmitter is identical to the G4 and both are used in the 80, 100 200, UrS and RS2 cars so you can easily find one at a wrecking yard or in a local parts store. Testing them is easy to do - just put your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector's end up) and 2 (2nd from the left on the black connector's side). 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 speed and position of the crankshaft in order to make a decision about timing of the fuel injectors, etc. To accomplish this, it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you are experiencing issues with either of these sensors, the diagnostic scanner will show codes that could lead to an engine shut down.

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

5. Tachometer

A malfunctioning engine sensor can cause a number of problems in your vehicle. It's a crucial component of the transmission in your audi car key case since it sends information to the ECU on how fast or slowly the car's engine is turning. This sensor can cause the transmission to malfunction and other car components to be affected.

The G5 engine speed sensor is situated on the edge of the transmission, above the flywheel ring gear and sends a signal to the ECU at pin T55/49 via a grey wire. The ECU utilizes this signal to control the flow of fuel and boost as well as timig. It also relays it to the G5 Tachometer in instrument cluster. You can check the sensor for failure by examining the continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should see approximately 1000 ohms resistance between those two pins. This is the same across the audi key programming tt key audi case - why not try this out, 80-100-200-RS2 model, ranging beginning with the 1985 MC and up to the 1997 UrS An and 1995 RS2 DU So, you may find good ones in wrecking yards.