Your Worst Nightmare About Audi G28 Bring To Life

How to Replace an Audi key shell G28 Engine Speed Sensor

In this video Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is located at the edge of transmission just above the flywheel gear. It transmits a signal to the ECU via a grey wire T55/49, then to the tachometer on the instrument cluster.

1. Engine Speed Sensor

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

The sensor is used to correlate with the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft reached TDC, and where the camshaft lies to trigger the spark and injectors.

If this sensor fails the ECU will display an error code P00160 which indicates that the Crank Shaft and Intake Camshaft aren't in sync and possibly indicating the chain stretching or a jump link on the upper chain of timing. However the code will not be displayed on its own without additional information from other sensors (G4 and G40).

It is a little tricky to test because there are several pins on the connector and each has its own functions. The best method for doing this is to measure the resistance between the ECU and the sensor. If the sensor is operational, it should be reading approximately 1000 ohms. If you are having problems with this component, look for signs of coolant or oil in the connector bay.

2. Injectors

Yesterday, while accelerating from the highway paytoll at a high speed I noticed a significant decrease in power. It was as if the engine was running out of gas. Or my injectors were not firing. I took out the spark plugs this morning and found that 3 were soaked in gasoline, and the fourth was dry. I put a piece of tissue over each injector hole, and Audi Key Shell when i start the engine without sparks, the 3 with gazoline jump out. The fourth one remains shut. I tested the ground connection on ECU pins 14/55,30/55 and 48/55 i get 0ohm. I think the issue is somewhere else.

I also tried to reset the PID without success. The car will start when the G28 is unplugged, and it is running fine with the G28 plugged in. However the intermittent misfire issue continues to occur at higher RPM. The coolant sensor (G62) even when unplugged, still shows an ice temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is zero.

I'm not certain what to do, i believe that i've eliminated everything else. I'm worried that i might have missed something. Please let me know should you have any suggestions! TIA!

3. Fuel Pump

The fuel pump of the g28 receives a signal from the RPM sensor. The GM-style sensor is identical to the G4 and both are used in the 80 100 200, UrS and RS2 cars which is why you can easily locate one at a wrecking yard or from a parts store. It is easy to test them: simply switch your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump on the connector's edge facing up). They should be infinite Ohms.

4. ECU

The ECU of our 20vt turbo (3B AAN ABY) engines must know the speed and position of the crankshaft in order to make a decision about timing of fuel injectors, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you have a problem with either of these sensors, the diagnostic scanner will show codes that could lead to an engine shutdown.

A failing G28 sensor could result in an inaccurate gearbox speed counter, a gearbox that shifts more quickly than normal, and/or a misfire in the gear. If you have any of these problems, it is likely that your sensor is deteriorating and requires replacement. They are cheap and easy-to-find particularly if they're an Bosch sensor like ours. Alternatively, the GM version of this part is also a good choice.

5. Tachometer

A failing engine sensor could cause a variety of issues within your vehicle. It's an essential component of the transmission in your Audi because it relays information to the ECU regarding how fast or slowly the engine of the car is turning. If this sensor fails, it will affect the performance of the transmission and the rest of the car's components.

The G5 engine speed sensor is located at the edge of the transmission just above the flywheel ring gear and sends a signal to the ECU at pin T55/49 via a grey wire. The ECU then uses and processes this signal to control the flow of fuel, timig and boost and then transmitting it to the G5 tachometer inside the instrument cluster. You can check the sensor for audi Key shell any failure by checking the continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. There should be an average resistance of 1000 ohms in these areas. This part is common across the audi car key 80-100-200-RS2 range, from the 1985 MC up to the 1997 UrS An and 1995 RS2 Du You may also find good ones in wrecking yards.