5 Laws Anyone Working In Audi G28 Should Be Aware Of

How to Replace an audi key G28 Engine Speed Sensor

In this video, Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is situated near the transmission's edge just above the flywheel gear. It transmits a signal to the ECU via a grey wire (T55/49) which is then sent to the tachometer within the instrument cluster.

1. Engine Speed Sensor

The grey wire is located on the edge of transmission, above the flywheel ring. The sensor transmits signals through the grey wire to pin T55/49. The ECU uses this information to regulate boost and fuel. It also sends a signal to the G5 tachometer in the instrument cluster.

The sensor is used to correlate the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft is TDC and where the camshaft is so it can trigger spark and injectors in the right way.

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

Testing can be a bit difficult since there are two connector pins, and they have different functions but the most effective way to test it is to measure the resistance between the sensor and the ECU. It should read around 1000 ohms when it is in full operation. Check for signs of coolant or oil in the connector bay if you are experiencing issues with this part.

2. Injectors

Yesterday accelerating full speed from highway paytoll i had a big cut in power like the engine is running out of gas or injectors are not firing anymore. I took out the spark plugs this morning, 3 were soaked in gasoline, and the fourth was unclean. I put tissue over each injector hole, and when i start the engine with no sparks, the ones that have gazoline pop right out. The 4th one remains shut. I tested the ground connection on ECU pins 14/55,30/55 and 48/55 I got zero Ohm. I'm assuming the issue is somewhere else.

I also tried to reset PID without success. The car key cover audi is able to start if the G28 is unplugged and it runs perfectly when it is plugged in however it is experiencing intermittent misfires at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature of -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows 2 bar when the actual pressure is 0.

I'm not sure what to do, as i think i've pretty much completely ruled out all other possibilities. But i am afraid I may have missed something. Let me know if you have any ideas! TIA!

3. Fuel Pump

The fuel pump in the g28 can be activated by a signal from the RPM sensor. The GM-style transmitter is identical to the G4 and both function in the 80 100 200, UrS and RS2 cars so you can easily find one at a salvage yard or at a parts store. It is simple to test them - put 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 must be infinite Ohms.

4. ECU

Our 20vt turbo (3B, AAN, ABY and ADU) engines are equipped with an ECU that has to know the speed and position of the crankshaft in order to make decisions about fuel injector timing etc. In order to do this it utilizes 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 the engine shutting down.

Some of the signs of a failed G28 sensor include an inaccurate rev counter for the gearbox and gears that shift faster than normal and/or a misfire when you are in gear. It is probable that the sensor is failing and requires to be replaced if you notice any of these signs. They're inexpensive and easy to locate, especially when they're an Bosch unit like ours. You can also choose the GM version of this component is also a good option.

5. Tachometer

A damaged engine sensor could cause a number of problems in your vehicle. It's an essential component of the transmission of your replacement audi a4 key since it sends information to the ECU on how fast or slowly the engine is turning. This sensor could cause the transmission to malfunction and other car components to be affected.

The G5 engine sensor is located at the outskirts of the transmission, over the flywheel ring. It transmits signals via gray wire to ECU pin T55/49. The ECU utilizes this signal to regulate fuel and boost, as well as timig. It also sends it to the G5 Tachometer in instrument cluster. You can check for sensor failure by checking continuity from the sensor to the tachometer. Additionally, you can examine the continuity between pins T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]), and between pin T6a/1 and pin T26a/12. There should be an average resistance of 1000 ohms between these two points. This is a standard part that is found across the audi car keys A1 Key Fob (Bookmark4You.Win) 80 100 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU, so the best ones could be available in wrecking yards.