20 Trailblazers Leading The Way In Audi G28

How to Replace an audi a3 key replacement car replacement key for audi a4 case (similar web site) G28 Engine Speed Sensor

In this video Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is located at the top of the transmission, above the flywheel ring gear. It transmits a signal the ECU via an uncolored wire (T55/49) and then to the tachometer located in the instrument cluster.

1. Engine Speed Sensor

Located on the edge of the transmission above the flywheel ring gear G28 Engine Speed Sensor sends signals to ECU pin T55/49 using a grey wire. The ECU uses this information to control the amount of fuel and boost. It also sends an indication to the G5 tachometer in the instrument cluster.

The sensor is used to link 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 according to the situation.

If this sensor fails the ECU will throw the P00160 error, which means the Crank Shaft and Intake Camshaft aren't in sync, possibly indicating the chain stretching 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).

Testing can be a bit difficult because there are two connector pins and they serve different purposes but the best method of testing it is to measure resistance between the sensor and the ECU. It should read approximately 1000 ohms if the sensor is operating at its maximum. If you are having problems with this part, check for evidence of coolant or oil in the connector bay.

2. Injectors

Yesterday, when accelerating from highway paytoll at maximum speed I noticed a massive drop in power. It was as if the engine had run out of gas. Or, my injectors weren't firing. I took out the spark plugs this morning and found that 3 were soaked with gasoline and the 4th was dry. When I start the engine, there are no sparks i put tissue on the top of each hole in the injector, the 3 drenched with gazoline jump out but the 4th stays closed. I inspected the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I got 0ohm. I think the issue is elsewhere.

I also tried to reset PID but without success. The car will start when the G28 is unplugged, and it is running 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 an ice temperature of -49c. Also, i noticed that the oil pressure gauge in the cockpit shows 2 bar while the actual pressure is 0.0 if i crank up the engine.

I'm not sure what to do, as i think i've pretty much eliminated everything else. But i am afraid I may have missed something. If anyone has suggestions, please chime in! TIA!

3. Fuel Pump

The fuel pump in the g28 can be activated by a signal sent from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. You can easily find a spare in a wrecking shop or parts store. It is simple to test them by putting your DMM in resistance mode and measure between pins 1 (with the bump on the connector end up) and 2 (2nd from left on the black connector's side). They should be infinite Ohms.

4. ECU

Our 20vt turbo (3B, AAN, ABY and ADU) engines are equipped with an ECU that must know the position and speed of the crankshaft in order to make decisions regarding timing of the fuel injector, replacement key for audi example. To accomplish this, it uses 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 cause an engine shut down.

A malfunctioning G28 sensor could result in an inaccurate speed counter for the gearbox, a gearbox that shifts faster than normal, or a misfire in gear. It is possible that your sensor is failing and requires to be replaced if you encounter any of these signs. The good news is they are very cheap and easily accessible, especially if you're looking at an Bosch sensor, which is what ours are. If you prefer, GM's version of this part is a good option.

5. Tachometer

A faulty engine speed sensor could be a cause for many issues in your vehicle. It's a crucial component of the transmission of your replacement key audi because it relays information to the ECU about how fast or slowly the engine of the car is turning. This sensor could cause the transmission to fail and other car components to be affected.

The G5 engine speed sensor is located at the edge of the transmission, above the flywheel ring gear. It sends a signal directly to the ECU at pin T55/49, via a grey wire. The ECU uses this signal to control the flow of fuel and boost and also timig. It also transmits it to the G5 Tachometer located in the instrument cluster. You can test the sensor for failure by examining the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should observe around 1000 ohms of resistance between those points. This is a standard part that is found across the audi tt key fob 80, 100, 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU. Good ones could be available in wrecking yards.