How To Outsmart Your Boss On Audi G28
How To Outsmart Your Boss On Audi G28
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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 at the top of the transmission above the flywheel ring 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 grey wire is located at the edges of the transmission, directly above the flywheel ring. The sensor sends signals through the grey wire to pin T55/49. The ECU utilizes this information to regulate fuel and boost. It also sends signals to the G5 tachometer in the instrument cluster.
The sensor is used to link the G40 Camshaft position Sensor. The ecu needs to be aware of when the crankshaft has reached TDC, and where the camshaft lies in order to activate the spark and injectors.
If this sensor fails, the ECU will display a P00160 code which means the Crank Shaft and Intake Camshaft are out of sync and could indicate the chain stretching or a jump link on the upper timing chain. However the code will not appear on its own, without additional information from other sensors (G4 and G40).
Testing can be a bit difficult as there are two different connector pins, and they have different functions but the most effective method to test it is to measure resistance between the sensor and the ECU. When the sensor is fully functional, it should read around 1000 ohms. Look for signs of coolant or oil in the connector bay if you are experiencing issues with this component.
2. Injectors
Yesterday, when accelerating from highway paytoll at full speed I noticed a massive reduction in power. It was as if the engine had run out of gas. Or my injectors were not firing. In the morning, i removed the spark plugs. Three were drenched with gazoline the 4th one was dry. I put a piece of tissue over each injector hole, and when I start the engine with no sparks, the ones with gazoline jump right out. The 4th one stays closed. I checked the ground connection on ECU pins 14/55,30/55 and 48/55 i get 0ohm. So i assume the problem is somewhere else.
I also tried to reset the PID with no success. The car will start when the G28 is not plugged in and it runs perfectly when it is plugged in but it still is experiencing intermittent misfires at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature of -49c, even if I unplug it. Also, i noticed that the gauge for oil pressure in the cockpit is showing 2 bar while the actual pressure is 0.0 when I crank up the engine.
I'm not sure what to do. I think I've ruled everything else out. But 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 in the g28 can be activated by a signal by the RPM sensor. The GM-style transmitter is similar to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. It is easy to find a spare in a wrecking shop or a parts store. Testing them is easy to do - just put your DMM in how much is a replacement audi key resistance mode and measure between pins 1 (with the bump on the connector's end up) and 2 (2nd from left on the black end of the connector). They should be infinite ohms.
4. ECU
Our 20vt turbo (3B, AAN, ABY and ADU) engines are equipped with an ECU that has to be aware of the speed and position of the crankshaft to make a decision about fuel injector timing etc. To do this, it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these sensors go wrong, you will receive codes on the diagnostic scanner which can lead to engine shutdown.
Some of the signs of a malfunctioning G28 sensor include an inaccurate gearbox rev counter, gears shifting quicker than normal, and/or a misfire when you are in gear. It is likely that the sensor is failing and requires to be replaced if you encounter any of these symptoms. They're cheap and easy to find, here especially if they're an Bosch unit like ours. Alternatively, the GM version of this part get more info is also a good option.
5. Tachometer
A damaged engine sensor could cause a variety of issues in your car. It is a crucial part of your Audi's transmission, as it sends information to the ECU about how fast or slow the vehicle's crankshaft is turning. This sensor could cause the transmission to malfunction and other car components to be affected.
The G5 engine speed sensor is located at the edge of the transmission above the flywheel audi a4 spare key ring gear. It transmits a signal to the ECU at pin T55/49, via an uncolored wire. The ECU then uses and processes the signal to control the flow of fuel, timig and boost as well as transmitting it to the G5 tachometer in the instrument cluster. You can determine if the sensor is in failure by examining the continuity from 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 [79]), and between click here pin T6a/1 as well as pin T26a/12. You should see around 1000 ohms of resistance between those two pins. This is a standard component across the Audi 80 100 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU so good parts could be found in wrecking yards.