A Look At The Ugly Real Truth Of Audi G28

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 outside of the transmission over the flywheel gear. It sends a message to the ECU through the grey wire T55/49 and then to the tachometer in the instrument cluster.

1. Engine Speed Sensor

The sensor is located at the edge of the transmission just above the flywheel ring gear G28 Engine Speed Sensor sends a signal to ECU pin T55/49 using the grey wire. The ECU then uses this information to control fuel, timig and boost. It also sends a signal to the G5 tachometer in the instrument cluster.

The sensor is used to link the G40 Camshaft position Sensor. The ecu has to know when the crankshaft reached TDC, and where the camshaft lies in order to activate the spark and injectors.

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 be a sign of an issue with the chain or a jumpy chain link in the upper timing chain. However, the error code won't appear on its own, without additional information from other sensors (G4 and G40).

Testing is a bit tricky since there are two connector pins and they have different functions however the best way to test it is to measure resistance between the sensor and the ECU. When the sensor is fully functional, it should read approximately 1000 ohms. If you're experiencing issues with this part, check for evidence of coolant or oil in the connector bay.

2. Injectors

Yesterday, while accelerating at full speed from the highway paytoll, I experienced a big cut in power as if the engine was running out of gas or the injectors aren't firing anymore. I took out the spark plugs this morning, 3 were soaked in gasoline, and the 4th was dry. I put tissue over each injector hole, and when i start the engine with no sparks, the 3 with gazoline jump out. The 4th one remains closed. I inspected the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ i get 0ohm. I'm assuming that the issue is somewhere else.

I also tried to reset the PID but with no luck. The car will start when the G28 is disconnected, but it runs fine with the G28 connected. However the intermittent misfire issue continues to occur at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature value of -49c, even if I unplug it. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is zero.

I'm not sure what to do, i believe that i've eliminated everything else. I'm concerned that i may have missed something. Let me know If you have any suggestions! website TIA!

3. Fuel Pump

The fuel pump in the g28 can be activated by a signal sent by the RPM sensor. The GM-style transmitter is similar to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily locate a spare in a wrecking shop or a parts store. It is simple to test them to do - just put your DMM in resistance mode and measure the here resistance between pins 1 (with the bump on the connector's end up) and 2 (2nd from the left on the black connector's end). They must be infinite Ohms.

4. ECU

The ECU of our 20vt turbo (3B AAN ABY) engines must be aware of the position and speed the crankshaft in order to make a decision about timing of the fuel injector, etc. To accomplish this, it makes use of a Crank Position click here Sensor (G4) and an Engine Speed Sensor (G28). If either of these go bad you will get codes on the diagnostic scanner which could cause engine shut down.

A damaged G28 sensor can cause an inaccurate gearbox speed counter or a gearbox that shifts more quickly 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. The good news is that they are quite affordable and easily accessible particularly when you're looking at a Bosch model, which is what we have. You can also choose the GM version of this unit is also a good option.

5. Tachometer

A malfunctioning engine speed sensor could be the reason behind many issues with your vehicle. It is a crucial part of your Audi's transmission, because it communicates to the ECU about how fast or slow the car's crankshaft is rotating. If the sensor fails, it could affect the performance of the transmission and the other car's components.

The G5 engine speed sensor is located at the edge of the transmission above the flywheel ring gear. It sends a signal to the ECU at pin T55/49, via a grey wire. The ECU then processes this signal to regulate the flow of fuel, timig and boost, and also transmitting it to the G5 Tachometer located in the instrument click here cluster. You can test for sensor failure by examining the continuity of the sensor to the tachometer. Also, 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. You should see approximately 1000 ohms of resistance between those two pins. This is a standard component across the Audi 80, 100, audi keys replacement 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU. Good ones might be availble in wrecking yards.