"Ask Me Anything " 10 Answers To Your Questions 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. This sensor is situated at the edge of transmission just above the flywheel gear. It transmits a signal to the ECU via an uncolored wire (T55/49) which is then sent to the tachometer in the instrument cluster.

1. Engine Speed Sensor

The grey wire is located at the edges of the transmission, above the flywheel ring. The sensor transmits signals through the grey wire to pin T55/49. The ECU then uses this information to control the boost, fuel, and timig. It also sends a signal to the G5 tachometer in the instrument cluster.

The sensor is used as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft has reached TDC, and where the camshaft lies in order to activate the spark and injectors.

If this sensor fails when it fails, the ECU will display a P00160 error code. This indicates that the Crank Shaft is not in alignment with the Intake Camshaft. It could also indicate an issue with the chain or a jump in the chain link of the upper timing chain. However, the error audi A3 key fob replacement code won't appear on its own without additional information from other sensors (G4 and G40).

Testing can be a bit difficult because there are two pins for the connector and they perform different functions however the best method of testing it is to measure resistance between the sensor and the ECU. It should read approximately 1000 ohms if the sensor is in full operation. Check for signs of coolant, or oil in the connector bay if you have issues with this component.

2. Injectors

Yesterday, while accelerating from the highway paytoll at maximum speed, i noticed a huge decrease in power. It was as if the engine had run out of gas. Or my injectors weren't firing. I took out the spark plugs this morning, three were soaked with gasoline and the 4th was dry. When I crank the engine with no sparks, I put a piece of tissue on the top of each of the injector holes and the 3 drenched with gazoline leap out, however the 4th one stays closed. I inspected the ground connection on ECU pins 14/55, 30/55 and 48/55. I got zero Ohm. I think the issue is elsewhere.

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 temperature sensor for the coolant (G62) shows the wrong temp value that is -49c even after unplugging it. Also, i noticed that the gauge for oil pressure in the cockpit is showing 2 bar when the actual pressure is 0.0 when I crank up the engine.

I don't know what to do. I believe that I've all other possibilities out. But i'm worried that i might have missed something. Please let me know should you have any suggestions! TIA!

3. Fuel Pump

The fuel pump on the g28 is activated by a signal sent by 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 parts store. It is simple to test them - just switch your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump on the connector's edge facing up). They must be infinite ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY, and ADU) engines have an ECU that must be aware of the speed and position of the crankshaft in order to make decisions regarding 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 badly, you will see codes on the diagnostic scanner which can cause the engine to shut down.

The signs of a malfunctioning G28 sensor include an inaccurate rev counter for the gearbox and gears that shift faster than normal and/or a misfire when you are in gear. It is likely that your sensor is failing and requires to be replaced if you experience any of these signs. The good thing is that they are quite affordable and easy to find, especially in the case of the Bosch unit like ours. Alternately, GM's version this component is an option.

5. Tachometer

A faulty engine speed sensor could be a cause for a slew of issues with your vehicle. It's a crucial component of the transmission of your audi car key replacement since it sends information to the ECU about how fast or slow the engine of the car is spinning. When this sensor fails, it will cause problems for the transmission and the rest of the car's components.

The G5 engine speed sensor is located at the outside of the transmission just above the flywheel ring gear. It sends a signal to the ECU at pin T55/49 via an uncolored wire. The ECU then processes this signal to control the flow of fuel, timig and boost and then sends it on to the G5 tachometer in the instrument cluster. You can test the sensor for failure by checking continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should see approximately 1000 ohms resistance between those points. This part is common across the Audi 80-100-200-RS2 model, ranging beginning with the 1985 MC and up to the 1997 UrS AN and the 1995 RS2 DU So, you may find good ones in wrecking yards.