Audi G28 10 Things I d Like To Have Learned Earlier

How to Replace an audi a4 key replacement G28 Engine Speed Sensor

In this video Charles the humble mechanic demonstrates how to replace audi key the G28 engine speed sensor. This sensor is located at the edge of transmission over the flywheel gear. It transmits a signal to the ECU via the grey wire (T55/49) and then to the tachometer located in the instrument cluster.

1. Engine Speed Sensor

The grey wire is located on the edge of transmission, just above the flywheel ring. This sensor sends a signal via the grey wire to pin T55/49. The ECU then utilizes this information to regulate the boost, fuel, and timig. It also sends an alert to the G5 Tachometer located in the instrument cluster.

The sensor is used as a reference for comparing with the G40 Camshaft Position Sensor. The ecu has to be aware of when the crankshaft has reached TDC, and the position of the camshaft, so that it can activate the spark and injectors.

If this sensor fails, the ECU will display an error code P00160. This indicates that the Crank Shaft is not in alignment with the Intake Camshaft. It could also be a sign of the possibility of a chain stretch or jumpy chain link in the upper timing chain. The code won't show without the additional information provided by other sensors (G4 or G40).

It is a little tricky to test as there are various connector pins, and each one has different functions. The best method for doing this is to measure the resistance between the ECU and the sensor. When the sensor is operational, it should read around 1000 ohms. If you're having issues with this sensor, look 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 as if the engine was running out of gas or the injectors aren't firing anymore. Today, i pulled out the spark plugs. Three were drenched in gazoline, audi keyless go the 4th one was dry. When i crank the engine with no sparks i put tissue on top of each injector hole, the 3 drenched with gazoline leap out, however the 4th stay shut. I inspected the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I get zero ohm. Therefore, i think the issue is elsewhere.

I also tried to reset the PID with no success. The car is able to start when the G28 is unplugged and runs fine when it is plugged in however it has intermittent misfire issues at higher RPM. The coolant sensor (G62) even when unplugged, still shows temperatures 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 think I've ruled everything else out. I'm afraid i may have missed something. If anyone has suggestions, please let me know! TIA!

3. Fuel Pump

The fuel pump of the g28 receives signals from the RPM sensor. The GM-style transmitter is identical to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. It is easy to find an extra in a wrecking shop or a parts store. It is easy to test them - just put 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 must be infinite ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY, and ADU) engines have an ECU that must know the position and speed of the crankshaft in order to make a decision about timing of the fuel injectors, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these go bad you will get codes on the diagnostic scanner which could cause engine shut down.

A malfunctioning G28 sensor could result in an inaccurate gearbox speed counter, a gearbox that shifts faster than normal, and/or an unfire when in the gear. It is likely that your sensor is failing and requires to be replaced if you notice any of these signs. They're cheap and easy to find particularly when they're an Bosch model like ours. Alternately, the GM version of this part is also a good choice.

5. Tachometer

A failing engine speed sensor could be the cause of numerous problems in your vehicle. It is an important part of the transmission of your Audi Replacement Key Service Near Me because it relays information to the ECU about how fast or slowly the engine is turning. When this sensor fails, it could cause problems for the transmission, as well as the rest of the car's components.

The G5 engine sensor is located at the outskirts of the transmission, just above the flywheel ring. It sends a signal via an uncolored wire to the ECU pin T55/49. The ECU is then able to process this signal to control fuel, timig, and boost and then sends it on to the G5 Tachometer located in the instrument cluster. You can test for sensor failure by examining the continuity from the sensor to the tachometer. Additionally, you can 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 and pin T26a/12. You should detect an average resistance of 1000 ohms in these areas. This is the same across the audi car key case 80-100-200-RS2 series, starting from the 1985 MC up to the 1997 UrS AN and 1995 RS2 DU, so you might find some good ones in wrecking yards.