How to Replace an audi spare key cost G28 Engine Speed Sensor

Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. This sensor is situated near the transmission's edge over the flywheel gear. It sends a signal to the ECU via a grey wire (T55/49) and then to the tachometer in the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated at the edges of the transmission, directly 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 flow of fuel, timig and boost. It also sends an indication to the G5 Tachometer within the instrument cluster.

The sensor serves as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft is TDC and the location of the camshaft so it can start spark and injectors accordingly.

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 be a sign of an issue with the chain or a jumped chain link in the upper timing chain. However, the error code won't be displayed on its own without additional information from other sensors (G4 and G40).

It's a bit tricky to test since there are several pins on the connector and they all have different functions. The most effective method to test it is by measuring the resistance between the ECU and the sensor. It should read approximately 1000 ohms if the sensor is at full operation. Look replacement key for audi a3 signs of coolant, or oil in the connector bay if you are experiencing issues with this component.

2. Injectors

Yesterday, while accelerating from the highway paytoll at a high speed I noticed a significant drop 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 fourth was unclean. When I crank the engine, there are no sparks, I put a piece of tissue on top of each injector hole and the 3 that were drenched in gazoline leap out, however the 4th stays shut. I tried to test the ground connections of ECU pins 14,30, and 48/55. I found zero ohm. I assume that the problem is somewhere else.

I also tried to reset the PID but with no luck. The car will start when the G28 is disconnected and runs fine when it is plugged in but it still has the intermittent misfire issue at higher RPM. The coolant sensor (G62) even if it is not plugged in, shows a temperature of -49c. I also noticed that the oil pressure gauge in the cockpit is showing 2 bar when the actual pressure is 0.0 when I crank up the engine.

I'm not sure what to do, as i believe that i've ruled out everything else. I'm worried that i might have missed something. Please let me know If you have any suggestions! TIA!

3. Fuel Pump

The fuel pump of the g28 receives signals from the RPM sensor. The GM-style transmitter is the same as the G4 and they both work in the 80 100, 200, UrS and RS2 cars so you can easily find one at a salvage yard or in a local parts store. It is simple to test them - just switch your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump at the connector's end facing upwards). They should be infinite Ohms.

4. ECU

The ECU of our 20vt turbo (3B AAN ABY) engines needs to be aware of the speed and position of the crankshaft in order to make a decision about fuel injector timing, etc. In order to do this it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these sensors go bad you will get codes on the diagnostic scanner that can cause the engine to shut down.

A malfunctioning G28 sensor can cause an inaccurate speed counter for your gearbox or a gearbox that shifts more quickly than normal, or a misfire in the gear. If you experience any of these issues it is most likely that your sensor is going bad and should be replaced. They're inexpensive and easy to locate especially when they're an Bosch unit like ours. Alternately, GM's version this component is an option.

5. Tachometer

A malfunctioning engine speed sensor could be a cause for a slew of issues with your vehicle. It is an important part of the transmission of your audi smart key replacement because it relays information to the ECU on how fast or slowly the car's engine is turning. When this sensor fails, it will disrupt the performance of the transmission as well as the rest of the audi car key replacement's components.

The G5 engine sensor is located at the edge of the transmission, just above the flywheel ring. It sends an electrical signal through a gray wire to the ECU pin T55/49. The ECU is then able to process 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 check the sensor for failure by checking continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should see an average resistance of 1000 ohms between these two points. This is a typical part that is found across the audi keys replacement cost 80, 100 200, UrS and Programming audi Key RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU so good parts could be found in wrecking yards.