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 at the edge of transmission over the flywheel gear. It sends a message to the ECU through 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 G28 Engine Speed Sensor sends signals to ECU pin T55/49 through the grey wire. The ECU then uses this information to control fuel, timig and boost. It also sends an indication to the G5 Tachometer located in the instrument cluster.
The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft is TDC and the location of the camshaft so it can activate spark and injectors in the right way.
If this sensor fails, the ECU will display a P00160 error code. This indicates that the Crank Shaft is out of alignment with the Intake Camshaft. It could also indicate an issue with the chain or a jump in the chain link of the upper chain. The code will not appear without the additional information provided by other sensors (G4 or G40).
Testing is a bit challenging because there are two connector pins, and they serve different purposes but the most effective method of testing it is by measuring resistance between the sensor and the ECU. If the sensor is operational, it should be reading approximately 1000 ohms. Examine for signs of coolant or oil in the connector bay if you have issues with this part.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at full speed, i noticed a huge drop in power. It was as if the engine was running out of gas. Or my injectors were not firing. I pulled out the spark plugs this morning, 3 were soaked with gasoline and the fourth was unclean. When I crank the engine with no sparks, I put a piece of tissue on top of each injector hole and the 3 drenched with gazoline pop out, but the 4th one stays shut. I tried to test the ground connections of ECU pins 14,30, and 48/55. I got 0ohm. I think the issue is somewhere else.
I also tried to reset the PID but with no luck. The car will start when the G28 is not plugged in and is running here fine when it is plugged in however it has the intermittent misfire issue at higher RPM. The coolant sensor (G62) even when it is unplugged, shows temperatures of -49c. I also noticed that the oil gauge in the cockpit shows 2 bars while the actual pressure is zero.
I'm not certain what to do, click here but i think i've pretty much completely ruled out all other possibilities. But i'm worried that I might have missed something. If anyone has suggestions, please share them! 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 identical to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. It is easy to find an extra in a wrecking shop or a parts store. It is simple to test them - just put your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector's end facing up). They must be infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY ADU) engines needs to know both 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 accomplish this. If you encounter a problem with either one of these, the diagnostic scanner will show codes that could cause the engine shutting down.
A failing G28 sensor could cause an inaccurate speed counter for the gearbox, a gearbox that shifts more quickly than normal, or a misfire while in the gear. It is probable that the sensor is failing and needs to be replaced if you experience any of these symptoms. They are cheap and easy-to-find particularly when they're a Bosch sensor like ours. You can also choose the GM version of more info this component is also a great option.
5. Tachometer
A faulty engine speed sensor could be the cause of numerous issues in your vehicle. It is a crucial part of your Audi's transmission, since it relays information to the ECU about how fast or slow the car's crankshaft is turning. This sensor could cause the transmission to fail and other car components to be affected.
The G5 engine sensor is located near the edge of the transmission, over the flywheel ring. It transmits signals via gray wire to ECU pin T55/49. The ECU utilizes this signal to regulate the amount of fuel and boost, and also to timigrate. It also sends it to the G5 Tachometer inside the instrument cluster. You can test the sensor for any failure by checking the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. It should show approximately 1000 ohms of resistance between those two pins. This is a common here feature across the Audi 80-100-200-RS2 model, ranging from the 1985 MC all the way up to the 1997 UrS AN more info and the 1995 RS2 DU You may also find some good ones in wrecking yards.