Why No One Cares About Audi G28

How to Replace an audi key G28 Engine Speed Sensor

In this video Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. This sensor is located near the transmission's edge over the flywheel gear. It transmits a signal to the ECU through a grey wire T55/49, then to the tachometer on the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated on the edge of transmission, above the flywheel ring. The sensor transmits a signal via 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 alert to the G5 Tachometer located in the instrument cluster.

The sensor is used to link the G40 Camshaft position Sensor. The ecu must know when the crankshaft has reached TDC, and the position of the camshaft, so that it can activate the spark and injectors.

If this sensor fails to function, the ECU will display a P00160 error code. This means that the Crank Shaft is out of alignment with the Intake Camshaft. It could also be a sign of a chain stretch or a jumped chain link in the upper chain. The code will not appear without the additional information provided by other sensors (G4 or G40).

Testing is a bit tricky because there are two connector pins and they have different functions but the best method to test it is by measuring resistance between the sensor and the ECU. If the sensor is operational, it should read about 1000 ohms. If you're experiencing issues with this part, check for evidence of coolant or oil in the connector bay.

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 the injectors are not firing at all. I took out the spark plugs this morning, three were drenched in gasoline and the 4th was dry. When I start the engine with no sparks i put tissue on the top of each of the injector holes, the 3 drenched with gazoline pop out, but the 4th one stays shut. I checked the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I get zero Ohm. So i assume the problem is elsewhere.

I also tried to reset PID but without success. The car will start when the G28 is disconnected, but it is running fine with the G28 plugged in. However, the intermittent misfire problem persists at higher RPM. The coolant sensor (G62) even when it is unplugged, shows temperatures of -49c. Also, i noticed that the gauge for oil pressure In My area the cockpit is showing 2 bar while the actual pressure is 0.0 when i rev the engine.

I'm not certain what to do, but i believe that i've eliminated everything else. But i'm worried that I may have missed something. If anyone has any suggestions, please let me know! TIA!

3. Fuel Pump

The fuel pump on the g28 is activated by a signal 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 so you can easily find one at a junkyard or at a parts store. Testing them is easy by putting your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector end up) and 2 (2nd from left on the black connector's end). They should be infinite Ohms.

4. ECU

Our 20vt turbo (3B, AAN, ABY and ADU) engines have an ECU that has to know the speed and position of the crankshaft to make decisions about fuel injector timing etc. To do this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these goes wrong, you will receive codes on the diagnostic scanner which could cause engine shut down.

Some of the symptoms of a failed G28 sensor include an inaccurate gearbox rev counter and gears that shift faster than normal and/or misfiring when in gear. It is likely that your sensor is failing and needs to be replaced if you experience any of these signs. The good news is that they are quite affordable and readily available, especially in the case of the Bosch model, like ours. If you prefer, GM's version of this part is a good option.

5. Tachometer

A damaged engine sensor audi Q7 key could cause a myriad of issues within your vehicle. It is an important part of the transmission in your audi key replacement cost uk, as it transmits information to the ECU about how fast or slow the engine of the car is spinning. This sensor could cause the transmission to malfunction and other car components to be affected.

The G5 engine speed sensor is located at the outside of the transmission above the flywheel ring gear. It sends a signal to the ECU at pin T55/49 through an uncolored wire. The ECU then uses and processes the signal to control the flow of fuel, timig and boost as well as transmitting it to the G5 tachometer in the instrument cluster. You can test the sensor for any failure by checking the continuity between it and the tachometer, between 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. You should observe approximately 1000 ohms of resistance between those two pins. This is a typical part that is found across the audi tt key 80 100, 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU, so the best ones might be availble in wrecking yards.