25 Shocking Facts About Audi G28
How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. This sensor is located near the transmission's edge over the flywheel gear. It transmits a signal to the ECU via the grey wire T55/49 and then to the tachometer in the instrument cluster.
1. Engine Speed Sensor
Located on the edge of the transmission, above the flywheel ring gear G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 via a grey wire. The ECU utilizes this information to regulate the amount of fuel and boost. It also sends an indication to the G5 tachometer in the instrument cluster.
The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu must be aware of when the crankshaft has reached TDC and also the position of the camshaft, to trigger the spark and injectors.
If this sensor fails the ECU will show a P00160 code which means the Crank Shaft and Intake Camshaft are out of sync, possibly indicating the chain is stretched or a jump link on 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 challenging because there are two pins for the connector and they perform different functions but the best method of testing it is to measure the resistance between the sensor and the ECU. When the sensor is fully operational, it should be reading around 1000 ohms. audi q7 locked keys in car for signs of coolant, or oil in the connector bay if you are experiencing problems with this part.
2. Injectors
Yesterday accelerating full speed from highway paytoll, I experienced an abrupt drop in power like the engine is out of gas or injectors are not firing at all. Today, i pulled out the spark plugs, 3 were drenched in gazoline, the fourth 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 leap out, however the 4th stays shut. I checked the ground connection of ECU pins 14,30, and 48/55. I found 0ohm. I think the issue is elsewhere.
I also tried to reset the PID but without success. The car will start when the G28 is not plugged in and runs fine when it is plugged in but it still is experiencing intermittent misfires at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature of -49c, even if I unplug it. Also, i noticed that the oil pressure gauge in the cockpit is showing 2 bar while the actual pressure is 0.0 if i crank up the engine.
I'm not sure what to do. I think I've all other possibilities out. But i'm worried that I may have missed something. If anyone has any ideas please let me know! TIA!
3. Fuel Pump
The fuel pump in the g28 receives signals from 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 parts store. It is easy to test them - simply switch your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector end facing up). They should be infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY) engines needs to know both the position and speed of the crankshaft to make decisions regarding timing of fuel injectors, etc. In order to do this it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these goes bad you will get codes on the diagnostic scanner which could cause engine shut down.
A malfunctioning G28 sensor can cause an inaccurate speed counter for your gearbox, a gearbox that shifts more quickly than normal, and/or an unfire when in the gear. It is possible that the sensor is failing and requires to be replaced if you encounter any of these symptoms. The good thing is that they are very cheap and easily accessible particularly when you're looking at a Bosch model, which is what we have. Alternately, the GM version of this component is also a good option.
5. audi replacement key uk failing engine speed sensor could be the cause of many issues in your car. It's an essential component of your Audi's transmission, because it communicates to the ECU about how fast or slow the vehicle's crankshaft is rotating. If this sensor fails, it could affect the performance of the transmission, as well as the other car's components.
The G5 engine sensor is located near the edge of transmission, above the flywheel ring. It sends a signal via a gray wire to the ECU pin T55/49. The ECU then uses and processes this signal to regulate fuel, timig, and boost and then transmitting it to the G5 tachometer in the instrument cluster. You can test the sensor for failure by checking continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. There should be the resistance to be around 1000 ohms between these points. This is a standard part across the Audi 80 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU, so the best ones might be availble in wrecking yards.