25 Shocking Facts About Audi G28

How to Replace an Audi G28 Engine Speed Sensor

Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. The sensor is situated near the edges of the transmission, above the flywheel ring gear. It sends a message to the ECU via the grey wire T55/49 and then to the tachometer located on the instrument cluster.

1. Engine Speed Sensor

The sensor is located at the edge of the transmission above the flywheel ring gear G28 Engine Speed Sensor sends signals to ECU pin T55/49 via the grey wire. The ECU then utilizes this information to regulate the flow of fuel, timig and boost. It also sends an alert to the G5 Tachometer in instrument cluster.

The sensor serves as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must be aware when the crankshaft is TDC and where the camshaft is so it can trigger spark and injectors accordingly.

If this sensor fails to function, the ECU will display a P00160 error code. This indicates that the Crank Shaft is out of sync with the Intake Camshaft. It could also indicate the possibility of a chain stretch or jumpy chain link in the upper chain of timing. However the code will not appear on its own without additional information from other sensors (G4 and G40).

Testing is a bit challenging since there are two pins for the connector and they perform different functions however the best way to test it is to measure the resistance between the sensor and the ECU. It should read about 1000 ohms if the sensor is in full operation. Examine for evidence of coolant or oil in the connector bay if you are experiencing problems with this part.

2. Injectors

Yesterday, while accelerating at full speed from the highway paytoll, i experienced an abrupt drop in power like the engine is out of gas or the injectors aren't firing any more. This morning i pull out the spark plugs, three were drenched with gazoline the fourth one was dry. I put tissue over each injector hole and when I turn the engine on without sparks, the three that have gazoline pop right out. The 4th one stays closed. I checked the ground connection of ECU pins 14,30, and 48/55. I got 0ohm. I'm assuming the issue is somewhere else.

I also tried to reset the PID but without success. The car key replacement audi will start if the G28 is disconnected and is running fine when it is connected but it still has intermittent misfire issues at higher RPM. The temperature sensor replacement key for audi a3 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 but the actual pressure is 0.

I'm not sure what to do. I think I've all other possibilities out. However, i'm afraid that I may have missed something. Please let me know should you have any suggestions! 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 and they both work in the 80 100 200, UrS and RS2 cars so you can easily find one at a wrecking yard or from a parts store. It is simple to test them - just switch your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump on the connector's edge facing upwards). They should be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY) engines requires to be aware of the position and speed of the crankshaft to make decisions regarding timing of the fuel injector, etc. In order to do this it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you have a problem with either of these sensors, the diagnostic scanner will display codes that could cause an engine shut down.

A failing G28 sensor could result in an inaccurate speed counter for the gearbox or a gearbox that shifts faster than normal, and/or a misfire while in the gear. It is possible that the sensor is failing and needs to be replaced if you experience any of these signs. The good news is that they are quite affordable and easy to find, especially in the case of a Bosch model, like ours. Alternatively, the GM version of this unit is also a good choice.

5. Tachometer

A failing engine speed sensor could be the cause of many issues with your vehicle. It's an essential component of the audi car key's transmission since it relays information to the ECU about how fast or slow the car's crankshaft is spinning. When this sensor fails, it will affect the performance of the transmission, as well as the other car's components.

The G5 engine sensor is located at the outskirts of the transmission, over the flywheel ring. It transmits signals via a gray wire to the ECU pin T55/49. The ECU uses this signal to regulate fuel and boost, as well as timig. It also transmits it to the G5 Tachometer located in the instrument cluster. You can determine if the sensor is in failure by checking continuity from the sensor programmers to the tachometer. You can also check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]) and between pin T6a/1 as well as pin T26a/12. You should detect a resistance of approximately 1000 ohms in these areas. This is a common part that is found across the replacement audi key cost 80 100, 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU so good parts could be found in wrecking yards.