4 Dirty Little Secrets About Audi G28 And The Audi G28 Industry

How to Replace an Audi G28 Engine Speed Sensor

In this video, Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is located on the edge of the transmission just above the flywheel ring gear. It transmits a signal the ECU via the grey wire (T55/49) which is then sent to the tachometer in 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 signals to ECU pin T55/49 via an uncolored wire. The ECU then utilizes this information to regulate the flow of fuel, timig and boost. It also sends signals to the G5 tachometer in the 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 activate spark and injectors in the right way.

If this sensor fails to function, 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 chain of timing. However, the error code won't be displayed on its own without additional information from other sensors (G4 and G40).

It's a bit tricky to test because there are various pins on the connector, and they all have different functions. The best way to do it is to measure the resistance between the ECU and the sensor. It should read about 1000 ohms when it is operating at its maximum. If you're experiencing issues with this component, look for signs of coolant or oil in the connector bay.

2. Injectors

Yesterday, as i was accelerating off the highway paytoll at full speed I noticed a significant decrease in power. It was like the engine was running out of gas. Or my injectors weren't firing. I took out the spark plugs this morning, 3 were soaked in gasoline, and the 4th was dry. When I crank the engine with no sparks, i place a tissue on top of each injector hole and the 3 drenched with gazoline jump out but the 4th one stays closed. I tested the ground connection of ECU pins 14,30 and 48/55. I got 0ohm. Therefore, i think the issue is somewhere else.

I also tried click here to reset the PID but without success. The car is able to start if the G28 is not plugged in and it runs perfectly when it is plugged in however it has the intermittent misfire issue at higher RPM. The coolant sensor (G62), even if it is not plugged in, shows temperatures of website -49c. Also, i noticed that the gauge for oil pressure in the cockpit shows 2 bar when the actual pressure is 0.0 if i crank up the engine.

I'm not sure what to do. I believe that I've ruled everything else out. But i am afraid i might have missed something. Let me know should you have any suggestions! TIA!

3. Fuel Pump

The fuel pump of the g28 gets a signal from 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 which is why you can easily locate one at a junkyard or from a parts store. It is simple to test them: simply switch your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump on the connector's edge facing upwards). They must be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY) engines must know both the position and speed the crankshaft to determine timing of the fuel injector, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you have a problem with either one of these, the diagnostic scanner will display the codes that could trigger an engine shut down.

Some of the symptoms of a failed G28 sensor are an inaccurate rev counter in the gearbox, gears shifting quicker than normal, and/or a misfire when you're in gear. It is probable that your sensor is failing and needs to be replaced if you encounter any of these symptoms. They're inexpensive and easy to locate especially if they're a Bosch sensor like ours. Alternately, GM's version this part would be an option.

5. Tachometer

A damaged engine sensor could cause a number of problems in your vehicle. It is an important part of the transmission in your Audi because it relays information to the ECU about how fast or slow the engine is turning. This sensor can cause the transmission to malfunction and other get more info car components to be affected.

The G5 engine sensor is located at the outskirts of the transmission, just above the flywheel ring. It transmits an electrical signal through an uncolored wire to the ECU pin T55/49. The ECU uses this signal to control the flow of fuel and boost and also timig. It also relays it to the G5 Tachometer inside the instrument cluster. You can test the sensor for failure by examining the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. get more info You should detect an average resistance of 1000 ohms between these points. This is the same across the Audi 80-100-200-RS2 audi car keys series, starting from the 1985 MC up to the 1997 UrS An and 1995 RS2 DU So, you may find good ones in wrecking yards.