Audi G28 10 Things I'd Love To Have Known In The Past
Audi G28 10 Things I'd Love To Have Known In The Past
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How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. The sensor is located on the edge of the transmission, above the flywheel ring gear. It sends a signal to the ECU via the grey wire (T55/49) which is then sent to the tachometer in the instrument cluster.
1. Engine Speed Sensor
The grey wire is situated at the edges of the transmission, directly above the flywheel ring. This sensor sends an electrical signal through the grey wire to pin T55/49. The ECU uses this information to regulate boost and fuel. It also sends an indicator to the G5 Tachometer in instrument cluster.
The sensor is used to link with the G40 Camshaft position Sensor. The ecu must be aware of when the crankshaft has reached TDC, and the location of the camshaft in order to activate the spark and injectors.
If this sensor fails, the ECU will display a P00160 error code. This means that the Crank Shaft is out of alignment with the Intake Camshaft. It could also indicate the possibility of a chain stretch or jump in the chain link of the upper chain of timing. The code won't appear without the additional information supplied by other sensors (G4 or G40).
It can be a bit difficult to test because there are different connector pins, and each one has different functions. The most effective method to test it is by measuring the resistance between the ECU and the sensor. If the sensor is functional, it should read around 1000 ohms. Check for signs of coolant, or oil in the connector bay if you are experiencing issues with this part.
2. Injectors
Yesterday accelerating full speed from highway paytoll, I experienced massive power loss as if the engine was running out of gas or the injectors aren't firing anymore. I pulled out the spark plugs this morning, 3 were soaked in gasoline, and the 4th was dry. I put a piece of tissue over each injector hole and when I turn the engine on without sparks, the three that have gazoline pop right out. The 4th one stays shut. I checked the ground connection on ECU pins 14/55, 30/55 and 48/55. I got 0ohm. I'm assuming that 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 runs fine with the G28 plugged in. However, the intermittent misfire problem persists at higher RPM. The coolant temperature sensor (G62) shows the wrong temperature value of -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows 2 bars when the more info actual pressure is zero.
I'm not certain what to do, i feel i have pretty much completely ruled out all other possibilities. But i'm worried that I may have missed something. 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 identical to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily find a spare in a wrecking shop or a parts store. Test them out by putting your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector's side up) and 2 (2nd from the left on the black connector's end). They should be infinite ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY ADU) engines requires to be aware of the position and speed the crankshaft to determine timing of the fuel injector, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If either of these go wrong, you will receive codes on the diagnostic scanner that can cause the engine to shut down.
A damaged G28 sensor could cause an inaccurate speed counter for the gearbox and a gearbox which shifts faster than normal, and/or an unfire when in gear. It is probable that your sensor is failing and needs to be replaced if you notice any of these signs. They are cheap and easy-to-find particularly in the case of a Bosch sensor like ours. more info If you prefer, GM's version of this part is a good option.
5. Tachometer
A damaged engine sensor could cause a number of problems in your car. 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. here This sensor can cause the transmission to malfunction and other 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 utilizes this signal to regulate here the flow of fuel and boost and also to timigrate. It also transmits it to the G5 Tachometer inside the instrument cluster. You can test the sensor for failure by checking continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should see a resistance of approximately 1000 ohms in these areas. This is the same across the Audi 80-100-200-RS2 series, starting from more info the 1985 MC up to the 1997 UrS AN and the 1995 RS2 DU, so you might find some good ones in wrecking yards.