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How to Replace an audi keys G28 Engine Speed Sensor

In this video Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is located near the transmission's edge, above the flywheel gear. It transmits a signal the ECU via an uncolored wire (T55/49) which is then sent to the tachometer within the instrument cluster.

1. Engine Speed Sensor

It is located on the outside of the transmission just above the flywheel ring gear the G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 through a grey wire. The ECU uses this information to control boost and fuel. It also sends an alert to the G5 Tachometer in instrument cluster.

The sensor is used to link the G40 Camshaft position Sensor. The ecu must be aware when the crankshaft is TDC and the location of the camshaft so it can start spark and injectors accordingly.

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

It can be a bit difficult to test as there are different connector pins, and they all have different functions. The best way to do it is to measure the resistance between the ECU and the sensor. It should read approximately 1000 ohms if the sensor is at full operation. Look 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 a high speed I noticed a significant drop in power. It was like the engine was running out of gas. Or my injectors weren't firing. I took out the spark plugs this morning, three were soaked in gasoline, and the fourth was unclean. I placed a tissue over each injector hole and when I start the engine with no sparks, the 3 with gazoline jump out. The 4th one stays closed. I checked the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I get 0ohm. I'm assuming the issue is in another place.

I also tried to reset the 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. I also noticed that the oil gauge in the cockpit shows 2 bar while the actual pressure is zero.

I'm not certain what to do, i believe that i've eliminated everything else. But i am afraid i might have missed something. If anyone has any ideas please share them! TIA!

3. Fuel Pump

The fuel pump in the g28 is activated by a signal sent from the RPM sensor. The GM-style transmitter 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 salvage yard 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's side up) and 2 (2nd from left on the black connector's side). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY, and ADU) engines have an ECU that needs to know the position and speed of the crankshaft in order to make decisions regarding fuel injector timing etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you encounter a problem with either of these sensors, the diagnostic scanner will display codes that could lead to the engine shutting down.

Some of the signs of a failing G28 sensor are an inaccurate rev counter in the gearbox the gears are shifting faster than normal, and/or a misfire when you're in gear. If you have any of these problems, it is likely your sensor is deteriorating and needs replacing. The good news is that they are very cheap and easily accessible, especially in the case of an Bosch sensor, like ours. If you prefer, GM's version of this part is a good option.

5. Tachometer

A malfunctioning engine speed sensor could be the cause of a slew of issues in your vehicle. It's a vital component of the replacement key audi audi keyfob key cost uk; reviews over at www.google.ps,'s transmission since it relays information to the ECU about how fast or slow the vehicle's crankshaft is rotating. This sensor can cause the transmission to fail and other components of the car to be affected.

The G5 engine sensor is located near the edge of the transmission, over the flywheel ring. It sends an electrical signal through an uncolored wire to the ECU pin T55/49. The ECU utilizes this signal to regulate fuel and boost, and also timig. It also sends it to the G5 Tachometer located in the instrument cluster. You can test for sensor failure by checking continuity from the sensor to the tachometer. Also, you can verify 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 around 1000 ohms of resistance between those two pins. This is a common feature across the replacement audi a4 key 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.