Audi G28: The Good The Bad And The Ugly

How to Replace an audi car key replacement cost G28 Engine Speed Sensor

In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. The sensor is situated on the edge of the transmission just above the flywheel ring gear. It transmits a signal to the ECU via an uncolored wire (T55/49) and then to the tachometer within the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated on the outside of the transmission, just above the flywheel ring. This sensor audi spare key Cost sends signals through the grey wire to pin T55/49. The ECU then uses this information to control fuel, timig and boost. It also sends an alert to the G5 Tachometer within the instrument cluster.

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

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

Testing is a bit tricky as there are two different connector pins and they perform different functions however the best way to test it is to measure resistance between the sensor and the ECU. It should read around 1000 ohms when it is at full operation. If you're having issues with this part, check for evidence of oil or coolant in the connector bay.

2. Injectors

Yesterday, while accelerating at full speed from the highway paytoll i had massive power loss like the engine is running out of gas or the injectors are not firing at all. I pulled out the spark plugs this morning and found that 3 were soaked in gasoline, and the 4th was dry. When I start the engine with no sparks i put tissue on top of each injector hole, the 3 drenched with gazoline jump out but the 4th stays closed. I tested the ground connection on ECU pins 14/55, 30/55 and 48/55. I got 0ohm. I assume that the problem is in another location.

I also tried to reset the PID but with no luck. The car will start when the G28 is disconnected, but it runs fine with the G28 connected. However, the intermittent misfire problem still occurs at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temp value -49c even when i unplug it. Also i noticed that the gauge for oil pressure in the cockpit shows 2 bar when the actual pressure is 0.0 if i crank up the engine.

I'm not certain what to do, but i think i've pretty much ruled out everything else. I'm afraid i may have missed something. If anyone has any suggestions, please chime in! TIA!

3. Fuel Pump

The fuel pump on the g28 is activated by a signal by 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 a spare in a wrecking shop or parts store. It is simple to test them - simply put your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector end facing upwards). They should be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY) engines requires to know the position and speed the crankshaft to make decisions regarding timing of the fuel injector, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these goes badly, you will see codes on the diagnostic scanner which can lead to engine shutdown.

A damaged G28 sensor could result in an inaccurate speed counter for your gearbox and a gearbox which shifts more quickly than normal, and/or a misfire in gear. It is possible that the sensor is failing and requires to be replaced if you experience any of these symptoms. The good news is that they are quite affordable and easy to find, especially in the case of the Bosch unit which is what we have. Alternatively, the GM version of this component is also a good option.

5. Tachometer

A failing engine speed sensor could be the cause of a slew of problems in your vehicle. It is an important part of the transmission of your audi key copy, as it transmits information to the ECU regarding how fast or slow the car's engine is spinning. This sensor can cause the transmission to malfunction and other components of the car to be affected.

The G5 engine speed sensor is located at the edge of the transmission, above the flywheel ring gear and Repairer sends a signal to the ECU at pin T55/49 through an uncolored wire. The ECU then processes this signal to regulate the flow of fuel, timig and boost and then transmitting it to the G5 tachometer in the instrument cluster. You can check the sensor for failure by checking continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should detect the resistance to be around 1000 ohms between these two points. This is a common feature across the audi a1 car key 80-100-200-RS2 model, ranging beginning with the 1985 MC and up to the 1997 UrS AN and the 1995 RS2 Du You may also find good ones in wrecking yards.