How to Replace an audi a3 replacement key G28 Engine Speed Sensor

Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. This sensor is located near the edges of the transmission just above the flywheel ring gear. It transmits a signal to the ECU via the grey wire (T55/49), then to the tachometer 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 an electrical signal to ECU pin T55/49 via a grey wire. The ECU then utilizes this information to regulate fuel, timig and boost. It also sends a signal to the G5 Tachometer located in the instrument cluster.

The sensor is used as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft is TDC and where the camshaft is so it can activate spark and injectors according to the situation.

If this sensor fails, the ECU will display an error code P00160 which indicates that the Crank Shaft and Intake Camshaft aren't in sync and possibly indicating the chain stretching 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).

It is a little tricky to test as there are different pins on the connector and each has its own functions. The best method for doing this is to measure the resistance between the ECU and the sensor. When the sensor is fully functional, it should read around 1000 ohms. If you're having issues with this sensor, look for signs of coolant or oil in the connector bay.

2. Injectors

Yesterday, as i was accelerating off the highway paytoll at maximum speed, i noticed a huge drop in power. It was like the engine had run out of gas. Or my injectors weren't firing. Today, i pulled out the spark plugs, 3 were soaked with gazoline and the fourth one was dry. When I crank the engine, there are no sparks i put tissue on the top of each hole in the injector, the 3 drenched with gazoline pop out, but the 4th stay shut. I tested the ground connection on ECU pins 14/55,30/55 and 48/55 i get 0ohm. So i assume the problem is somewhere else.

I also tried to reset PID but without success. The car will start when the G28 is unplugged, and it runs fine with the G28 connected. However, the intermittent misfire problem persists at higher RPM. The coolant sensor (G62), even if it is not plugged in, shows an ice temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bars while the actual pressure is 0.

I'm not sure what to do. I feel like i've pretty much ruled everything else out. I'm concerned that i may have missed something. If anyone has any suggestions, please let me know! TIA!

3. Fuel Pump

The fuel pump in the g28 is activated by a signal sent by the RPM sensor. The GM-style transmitter is similar to the G4 sender, and both operate on the 80,100,200, UrS, audi a3 key Fob and RS2 vehicles. You can easily find a spare in a wrecking shop or parts store. Testing them is easy by putting your DMM in resistance mode and measure between pins 1 (with the bump on the connector's side up) and 2 (2nd from the left on the black connector's end). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B, AAN, ABY and ADU) engines have an ECU that needs to be aware of the speed and position of the crankshaft to make a decision about timing of the fuel injectors, 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 malfunctioning G28 sensor can cause an inaccurate speed counter for your gearbox or a gearbox that shifts faster than normal, and/or a misfire in gear. If you experience any of these problems, it is most likely that your sensor is going bad and requires replacement. They're inexpensive and easy to locate particularly if they're a Bosch model like ours. You can also choose the GM version of this component is also a good option.

5. Tachometer

A malfunctioning engine speed sensor could be the reason behind numerous problems in your vehicle. It's a crucial component of the transmission in your audi replacement key service near Me because it relays information to the ECU regarding how fast or slow the car's engine is spinning. This sensor could cause the transmission to fail and other components of the car to be affected.

The G5 engine sensor is located at the outskirts of the transmission, just above the flywheel ring. It transmits a signal via an uncolored wire to the ECU pin T55/49. The ECU utilizes this signal to regulate the amount of fuel and boost, as well as timig. It also transmits it to the G5 Tachometer inside the instrument cluster. You can check the sensor for failure by checking continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should observe approximately 1000 ohms of resistance between these two points. This is a common feature across the audi a1 key fob 80-100-200-RS2 range, from the 1985 MC all the way up to the 1997 UrS AN and 1995 RS2 Du You may also find them in wrecking yards.