4 Dirty Little Tips On Audi G28 Industry Audi G28 Industry

How to Replace an Audi G28 Engine Speed Sensor

In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. The sensor is situated near the edges of the transmission just above the flywheel ring gear. It transmits a signal to the ECU through the grey wire T55/49 and then to the tachometer located on the instrument cluster.

1. Engine Speed Sensor

The sensor is located at the edge of the transmission, above the flywheel ring gear the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 through the grey wire. The ECU uses this information to control fuel and boost. It also sends an indication to the G5 tachometer in the instrument cluster.

The sensor serves as a reference for comparing 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 according to the situation.

If this sensor fails, the ECU will display a P00160 error code. This indicates that the Crank Shaft is out of alignment with the Intake Camshaft. It could also be a sign of the possibility of a chain stretch or jumpy chain link in the upper timing chain. However the code will not appear on its own, without additional information from other sensors (G4 and G40).

It's a bit tricky to test because there are different pins on the connector, and each has its own functions. The best method for doing this is by measuring the resistance between the ECU and the sensor. It should read approximately 1000 ohms when the sensor is at full operation. If you're having issues with this part, check for signs of coolant or oil in the connector bay.

2. Injectors

Yesterday, while accelerating at full speed from the highway paytoll, I experienced a big cut in power like the engine is running out of gas or injectors aren't firing any more. I pulled out the spark plugs this morning, 3 were drenched in gasoline and the fourth was unclean. When I start the engine without sparks, i place a tissue on the top of each hole in the injector, the 3 drenched with gazoline leap out, however the 4th stay closed. I inspected the ground connection on ECU pins 14/55, 30/55 and 48/55. i get 0ohm. Therefore, i think the issue is elsewhere.

I also tried to reset PID without success. The car will start when the G28 is disconnected, but it works fine when the G28 connected. However, the intermittent misfire problem continues to occur at higher RPM. The coolant sensor (G62), even when unplugged, still shows an ice temperature 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 don't know what to do. I believe that I've eliminated everything else. I'm concerned that i may have missed something. If anyone has suggestions, please share them! TIA!

3. Fuel Pump

The fuel pump on the g28 is activated by a signal sent by the RPM sensor. The GM-style transmitter functions similarly to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily find the spare in a salvage shop or 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 upwards). 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 position and speed of the crankshaft to make a decision about fuel injector timing etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you encounter a problem with either of these, the diagnostic scanner will show codes that could lead to an engine shut down.

A damaged G28 sensor could result in an inaccurate speed counter for the gearbox or a gearbox that shifts faster than normal, and/or an unfire when in gear. If you have any of these issues it is likely that your sensor is deteriorating and requires replacement audi keys. They are cheap and easy-to-find, especially if they're an Bosch unit like ours. Alternately, the GM version of this component is also a good choice.

5. Tachometer

A faulty engine speed sensor could be the reason behind many issues in your vehicle. It's a vital component of your new audi key's transmission, as it sends information to the ECU about how fast or slow the vehicle's crankshaft is spinning. When this sensor fails, it could affect the performance of 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 is then able to process this signal to regulate fuel, timig, and boost, and also transmitting it to the G5 tachometer 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 via pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. There should be an average resistance of 1000 ohms between these two points. This is a common component across the audi connect key 80 100, 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU, so the best ones could be available in wrecking yards.