Notes

Audi G28: 10 Things I'd Like To Have Known Sooner
How to Replace an Audi G28 Engine Speed Sensor

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

1. Engine Speed Sensor

The grey wire is located at the edges of the transmission, above the flywheel ring. The sensor sends an electrical signal through the grey wire to pin T55/49. The ECU uses this information to control the amount of fuel and boost. It also sends a signal to the G5 tachometer in the instrument cluster.

The sensor is used to connect the G40 Camshaft position Sensor. The ecu has to know when the crankshaft reached TDC and also the position of the camshaft, in order to activate the spark and injectors.

If this sensor fails when it fails, the ECU will display a P00160 error message. This indicates that the Crank Shaft is not in sync with the Intake Camshaft. It could also be a sign of an issue with the chain or a jumped chain link in 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 challenging because there are two connector pins, and they have different functions but the best method to test it is to measure the resistance between the sensor and the ECU. It should read about 1000 ohms when it is in full operation. If you're experiencing issues with this part, check for evidence of coolant or oil in the connector bay.

2. audi car key replacement accelerating full speed from highway paytoll i had an abrupt drop in power like the engine is running out of gas or the injectors aren't firing at all. Today, i pulled out the spark plugs, three were drenched in gazoline, the fourth one was dry. I placed a tissue over each injector hole, and when I start the engine without sparks, the three with gazoline jump out. The fourth one remains shut. I inspected the ground connection on ECU pins 14/55,30/55 and 48/55 I get zero Ohm. I assume that the problem is in another location.

I also tried to reset the PID without success. The car will start when the G28 is disconnected, but it runs fine with the G28 plugged in. However the intermittent misfire issue continues to occur at higher RPM. The coolant sensor (G62), even if it is not plugged in, shows a temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bars when the actual pressure is zero.

I'm not certain what to do, as i think i've pretty much eliminated everything else. But i'm worried that i might have missed something. If anyone has any ideas 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 functions similarly to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. You can easily locate a spare in a wrecking shop or a parts store. It is easy to test them - just switch your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump at the connector end facing upwards). They must be infinite Ohms.


4. ECU

The ECU in our 20vt turbo (3B AAN ABY ADU) engines needs to know the position and speed the crankshaft to make decisions regarding fuel injector timing, etc. To do this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these sensors go wrong, you will receive codes on the diagnostic scanner that can cause the engine to shut down.

A failing G28 sensor could cause an inaccurate gearbox speed counter or a gearbox that shifts faster than normal, or a misfire in gear. If you have any of these problems, it is likely your sensor is deteriorating and needs replacing. They're cheap and easy to find, especially in the case of a Bosch sensor like ours. Alternatively, GM's version of this component is an excellent choice.

5. Tachometer

A failing engine speed sensor could be the reason behind many problems in your car. It is a crucial part of your Audi's transmission, because it communicates to the ECU about how the car's crankshaft is rotating. This sensor could cause the transmission to malfunction and other components of the car to be affected.

The G5 engine speed sensor is situated on the outside of the transmission, above the flywheel ring gear and sends a signal to the ECU at pin T55/49 via an uncolored wire. The ECU is then able to process the signal to control the flow of fuel, timig and boost, and also transmitting it to the G5 tachometer in the instrument cluster. You can check the sensor for failure by examining the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79trace [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 part that is found across the Audi 80 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU. Good ones could be available in wrecking yards.

Homepage: https://www.g28carkeys.co.uk/audi-car-key-replacements-near-me/