5 Laws Anybody Working In Audi G28 Should Be Aware Of

How to replace audi key an Audi G28 Engine Speed Sensor

In this video, Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is located near the transmission's edge just above the flywheel gear. It transmits a signal the ECU via a grey wire (T55/49), then to the tachometer within the instrument cluster.

1. Engine Speed Sensor

Located on the edge of the transmission above the flywheel ring gear the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 through a grey wire. The ECU then utilizes this information to regulate fuel, timig and boost. It also sends an indication to the G5 Tachometer in instrument cluster.

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

If this sensor fails, the ECU will throw a P00160 code which means the Crank Shaft and Intake Camshaft are not in sync, possibly indicating the chain is stretched or a jump link on the upper timing chain. The code will not appear without the additional information supplied by other sensors (G4 or G40).

Testing is a bit tricky because there are two connector pins, and they perform different functions however the best method of testing it is by measuring resistance between the sensor and audikey the ECU. It should read around 1000 ohms if the sensor is operating at its maximum. Examine for signs of coolant, or oil in the connector bay if you have issues with this component.

2. Injectors

Yesterday, when i was accelerating to the fullest speed from highway paytoll i had an abrupt drop in power like the engine is running out of gas or injectors aren't firing at all. I pulled out the spark plugs this morning, three were soaked with gasoline and the fourth was dry. I put a piece of tissue over each injector hole, and when i turn the engine on without sparks, the three that have gazoline pop right out. The 4th one remains shut. I checked the ground connection of ECU pins 14,30 and 48/55. I found zero ohm. I'm assuming that the issue is in another location.

I also tried to reset the PID but with no luck. The car will start when the G28 is disconnected, but it runs fine with the G28 plugged in. However the intermittent misfire issue continues to occur at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature of that is -49c even after unplugging it. 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 don't know what to do. I believe that I've all other possibilities out. But i'm worried that I may have missed something. If anyone has any ideas please let me know! TIA!

3. Fuel Pump

The fuel pump in the g28 gets a signal from the RPM sensor. The GM-style transmitter is identical to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. It is easy to find a spare in a wrecking shop or a parts store. Test them out by putting your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector's side up) and 2 (2nd from the left on the black connector's side). They must be infinite Ohms.

4. ECU

The ECU of our 20vt turbo (3B AAN ABY ADU) engines requires to be aware of the speed and position of the crankshaft to determine timing of 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, the diagnostic scanner will show codes that could lead to an engine shutdown.

A failing G28 sensor can cause an inaccurate gearbox speed counter, a gearbox that shifts faster than normal, and/or a misfire in gear. If you have any of these problems, it is likely your sensor is going bad and audi a1 key fob requires replacement. They're cheap and easy to find particularly in the case of an Bosch model like ours. Alternately, the GM version of this component is also a good option.

5. Tachometer

A damaged engine sensor could cause a variety of issues within your vehicle. It's an essential component of the transmission in your programming audi key, as it transmits information to the ECU about how fast or slow the car's engine is turning. This sensor can cause the transmission to malfunction and other components in the car to be affected.

The G5 engine sensor is located at the edge of the transmission, over the flywheel ring. It transmits a signal via gray wire to ECU pin T55/49. The ECU is then able to process the signal to control fuel, timig and boost, and also transmitting it to the G5 Tachometer located in the instrument cluster. You can determine if the sensor is in failure by examining the continuity from the sensor to the tachometer. You can also check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]), and between pin T6a/1 and pin T26a/12. You should observe approximately 1000 ohms resistance between those points. This is the same across the audi car key replacement cost 80-100-200-RS2 range, from the 1985 MC all the way up to the 1997 UrS An and 1995 RS2 DU, so you might find some good ones in wrecking yards.