Why You Should Concentrate On Improving Audi G28

How to Replace an audi etron key G28 Engine Speed Sensor

Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. This sensor is situated near the transmission's edge, above the flywheel gear. It transmits a signal to the ECU via the grey wire (T55/49) which is then sent to the tachometer within the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated at the edges of the transmission, just above the flywheel ring. The sensor transmits a signal via the grey wire to pin T55/49. The ECU utilizes this information to regulate fuel and boost. It also sends an alert to the G5 Tachometer located in the instrument cluster.

The sensor is used to connect the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft reached TDC, and where the camshaft lies so that it can activate the spark and injectors.

If this sensor fails, the ECU will display an error code P00160. This means that the Crank Shaft is not in sync with the Intake Camshaft. It could also indicate a chain stretch or a jump in the chain link of the upper timing chain. The code will not appear without the additional information provided by other sensors (G4 or G40).

It is a little tricky to test because there are several pins on the connector, 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 be reading around 1000 ohms. If you are having problems with this sensor, look for evidence of coolant or oil in the connector bay.

2. Injectors

Yesterday, while accelerating from the highway paytoll at a high speed I noticed a significant decrease in power. It was like the engine was running out of gas. Or my injectors were not firing. I took out the spark plugs this morning, 3 were drenched in gasoline and the fourth was dry. When i crank the engine, there are no sparks, I put a piece of tissue on the top of each of the injector holes, the 3 drenched with gazoline jump out but the 4th stays shut. I tested the ground connection of ECU pins 14,30 and 48/55. I got zero ohm. I'm assuming that the issue is elsewhere.

I also tried to reset the PID without success. The car will start when the G28 is not plugged in and is running fine when it is plugged in, but still has the intermittent misfire issue at higher RPM. The coolant sensor (G62), even when unplugged, still shows temperatures of -49c. I also noticed that the gauge for oil pressure in the cockpit is showing 2 bar while the actual pressure is 0.0 when I crank up the engine.

I'm not sure what to do, as i believe that i've completely ruled out all other possibilities. But i'm worried that i might have missed something. If anyone has any suggestions, please let me know! TIA!

3. Fuel Pump

The fuel pump of the g28 receives a signal from the RPM sensor. The GM-style transmitter is identical to the G4 and both are used in the 80 100, 200, UrS and RS2 cars so you can easily find one at a salvage yard or from a parts store. Test them out - put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's side up) and 2 (2nd from left on the black end of the connector). They must be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY ADU) engines must know both the position and speed the crankshaft to make decisions regarding timing of the fuel injector, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these go badly, you will see codes on the diagnostic scanner which could cause engine shut down.

A failing G28 sensor could result in an inaccurate speed counter for the gearbox and a gearbox which shifts faster than normal, and/or an unfire when in the gear. If you are experiencing any of these problems, it is likely that your sensor is going bad and requires replacement audi key fob. The good thing is that they are very cheap and easily accessible particularly if you're looking at an Bosch sensor, like ours. Alternately, GM's version this part would be an excellent choice.

5. Tachometer

A malfunctioning engine sensor can cause a myriad of issues within your vehicle. It's a crucial component of the transmission in your Audi because it relays information to the ECU about how fast or slow the engine is spinning. This sensor can cause the transmission to fail and other car components to be affected.

The G5 engine speed sensor is located on the outside of the transmission above the flywheel ring gear and sends a signal to the ECU at pin T55/49 via a grey wire. The ECU utilizes this signal to regulate the amount of fuel and boost, as well as timig. It also relays 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 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 see an average resistance of 1000 ohms between these two points. This is the same across the audi replacement key service near me smart key replacement, demilked.com, 80-100-200-RS2 model, ranging from the 1985 MC all the way up to the 1997 UrS An and 1995 RS2 Du You may also find some good ones in wrecking yards.