20 Trailblazers Setting The Standard In Audi G28
20 Trailblazers Setting The Standard In Audi G28
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How to Replace an Audi G28 Engine Speed Sensor
In this video Charles the Humble Mechanic shows 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 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 on the edge of transmission, directly above the flywheel ring. This sensor sends a signal via the grey wire to pin T55/49. The ECU uses this information to control fuel and boost. It also sends an indicator to the G5 Tachometer within the instrument cluster.
The sensor is used to connect with the G40 Camshaft position Sensor. The ecu has to know when the crankshaft reached TDC, and the position of the camshaft, to trigger the spark and injectors.
If this sensor fails the ECU will display a P00160 code which means the Crank Shaft and Intake Camshaft are not in sync and could indicate the chain stretching or a jump link on the upper timing chain. The code won't appear without the additional information provided by other sensors (G4 or G40).
It's a bit tricky to test since there are several pins on the connector and they all have different functions. The best method for doing this is to measure the resistance between the ECU and the sensor. It should read about 1000 ohms when it is in full operation. Examine for signs of coolant, or oil in the connector bay if you are experiencing issues with this component.
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. This morning i pull out the spark plugs, three were drenched with gazoline the 4th one was dry. When I start the engine without sparks, I put a piece of tissue on top of each injector hole, the 3 drenched with gazoline jump out but the 4th stay closed. I tested the ground connection on ECU pins 14/55, 30/55 and 48/55. I get zero ohm. I'm assuming that the issue is in another location.
I also tried to reset the PID but without success. The car can start if the G28 is unplugged and is running fine when it is connected however it has intermittent misfire issues 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 when the actual pressure is 0.
I don't know what to do. I think I've ruled everything else out. But i am afraid 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 from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. You can easily locate an extra in a wrecking shop or parts store. It is simple 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
Our 20vt turbo (3B, AAN, ABY and ADU) engines are equipped with an ECU that must be aware of the speed and position of the crankshaft in order to make a decision about timing of the fuel injector, for example. To do this, it makes use of a Crank Position Sensor (G4) and an Engine Speed more info Sensor (G28). If you encounter a problem with either one of these, the diagnostic scanner will show codes that could cause an engine shutdown.
A failing G28 sensor could cause an inaccurate gearbox speed counter or a gearbox that shifts faster than normal, and/or a misfire while in gear. If you get more info have any of these issues, it is likely your sensor is deteriorating and should be replaced. They're inexpensive and easy to locate, especially in the case of a Bosch sensor like ours. Alternately, the GM version of more info this part is also a great option.
5. Tachometer
A failing engine speed sensor could be a cause for many issues with your vehicle. It's an essential component of your Audi's transmission, since it relays information to the ECU about how fast or slow the car's crankshaft is spinning. If the sensor fails, it could cause problems for the transmission and the other car's components.
The G5 engine sensor is located at the click here edge of the transmission, just above the flywheel ring. It sends signals via a gray wire to the ECU pin T55/49. The ECU is then able to process the signal to control fuel, timig and boost as well as transmitting it to the G5 Tachometer located in the instrument cluster. You can website determine if the sensor is in 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 as well as pin T26a/12. You should see the resistance to be around 1000 ohms between these points. This is a typical part across the Audi 80, 100 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU. Good parts could be found in wrecking yards.