How To Beat Your Boss Audi G28

How to Replace an audi tt key replacement 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 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 at the edges of the transmission, above the flywheel ring. This sensor sends an electrical signal through the grey wire to pin T55/49. The ECU uses this information to control fuel and boost. It also sends an indication to the G5 Tachometer within the instrument cluster.

The sensor is used as a reference to correlate with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft has reached TDC and also where the camshaft lies in order to activate the spark and injectors.

If this sensor fails, the ECU will show the P00160 error, which means the Crank Shaft and Intake Camshaft are not in sync and could indicate the chain stretching or a jump link on the upper chain of timing. 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 as there are several connector pins, and they all have different functions. The best method for doing this is to measure the resistance between the ECU and the sensor. When the sensor is operational, it should read about 1000 ohms. Check for signs of coolant, or oil in the connector bay if there are issues with this part.

2. Injectors

Yesterday, while accelerating from the highway paytoll at full speed I noticed a massive reduction in power. It was as if the engine was running out of gas. Or, my injectors weren't firing. I took out the spark plugs this morning, 3 were drenched in gasoline and the 4th was dry. I put a piece of tissue over each injector hole and when i start the engine without sparks, the three with gazoline jump right out. The fourth one remains shut. I inspected the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I get zero ohm. Therefore, i think the issue is somewhere else.

I also tried to reset the PID but without success. The car will start when the G28 is unplugged, and it runs fine with the G28 plugged in. However the intermittent misfire issue still occurs at higher RPM. The coolant sensor (G62), even when it is unplugged, shows a temperature of -49c. I also noticed that the oil pressure gauge in the cockpit shows 2 bar when the actual pressure is 0.0 if i crank up the engine.

I'm not sure what to do. I feel like i've pretty much eliminated everything else. However, i'm afraid that I may have missed something. Let me know should 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 identical to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. It is easy to find the spare in a salvage shop or a parts store. It is simple to test them - just put your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector end facing up). They should be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY) engines must know both the position and speed the crankshaft in order to make a decision about fuel injector timing, etc. In order to do this it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these goes badly, you will see codes on the diagnostic scanner that can cause the engine to shut down.

The signs of a malfunctioning G28 sensor include an inaccurate gearbox rev counter and gears that shift faster than normal and/or misfiring when in gear. If you are experiencing any of these problems, it is likely your sensor is failing and needs replacing. They are cheap and easy-to-find especially in the case of a Bosch model like ours. Alternately, the GM version of this component is also a good option.

5. Tachometer

A faulty engine speed sensor could be a cause for many problems in your vehicle. It is a crucial part of the audi replacement key cost a5 key fob (maps.google.com.br)'s transmission since it relays information to the ECU about how fast or slow the vehicle's crankshaft is turning. This sensor can cause the transmission to malfunction and other car components to be affected.

The G5 engine sensor is located at the edge of the transmission, just above the flywheel ring. It transmits signals via gray wire to ECU pin T55/49. The ECU uses this signal to regulate the amount of fuel and boost, and also to timigrate. It also sends it to the G5 Tachometer located in the instrument cluster. You can determine if the sensor is in failure by checking 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 [79trace [79]), and between pin T6a/1 as well as pin T26a/12. You should see approximately 1000 ohms of resistance between those points. This is a common component across the audi car keys 80 100, 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU. Good parts could be found in wrecking yards.