Why Audi G28 Isn't A Topic That People Are Interested In Audi G28
Why Audi G28 Isn't A Topic That People Are Interested In Audi G28
Blog Article
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 situated at the top of the transmission just above the flywheel ring gear. It transmits a signal the ECU via an uncolored wire (T55/49) and then to the tachometer within the instrument cluster.
1. Engine Speed Sensor
Located on the edge of the transmission, above the flywheel ring gear the G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 using the grey wire. The ECU then utilizes this information to regulate fuel, timig and boost. It also sends a signal 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 where the camshaft is located so that it can trigger spark and injectors according to the situation.
If this sensor fails, the ECU will show a P00160 code which means the Crank Shaft and Intake Camshaft are out of sync and possibly indicating chain stretch or a jumped 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 is a bit tricky because there are two connector pins and they perform different functions however the best method to test it is to measure the resistance between the sensor and the ECU. It should read approximately 1000 ohms if the sensor is in full operation. If you're experiencing issues with this component, look for signs of coolant or oil in the connector bay.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at full speed I noticed a significant decrease in power. It was like the engine was running out of gas. Or my injectors weren't firing. Today, i pulled out the spark plugs. Three were drenched in gazoline, the 4th one was dry. When I start the engine, there are no sparks, I put a piece of tissue on the top of each hole in the injector, the 3 drenched with gazoline pop out, but the 4th stays closed. I tried to test the ground connections of ECU pins 14,30, and 48/55. I got zero ohm. So i assume the problem is elsewhere.
I also tried to reset the PID without success. The car can start when the G28 is unplugged and runs fine when it is plugged in but it still has the intermittent misfire issue at higher RPM. The coolant sensor (G62), even when unplugged, still shows temperatures of -49c. I also noticed that the gauge for oil pressure in the cockpit shows 2 bar when the actual pressure is 0.0 when I crank up the engine.
I'm not sure what to do. I feel like i've pretty much ruled everything else out. I'm afraid i may have missed something. If anyone has any ideas please chime in! TIA!
3. Fuel Pump
The fuel pump in the g28 receives a signal from the RPM sensor. The GM-style sensor is the same as the G4 and both are used in the 80 100, 200, UrS and RS2 cars which is why you can easily locate one at a junkyard or in a local parts store. It is simple to test them - simply put your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump on the connector's edge facing upwards). They must be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY and ADU) engines have an ECU that needs to be aware of the speed and position of the crankshaft in order 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 you are experiencing issues with either of these sensors, the diagnostic scanner will display codes that could lead to an engine shutdown.
A malfunctioning G28 sensor could result in an inaccurate speed counter for the gearbox, a gearbox that shifts more quickly than normal, and/or website a misfire in gear. If you are experiencing any of these issues, it is likely that your sensor is deteriorating and needs replacing. The good news is that they are very affordable and easy to find, especially in the case of a Bosch sensor, which is what ours are. Alternatively, the GM version of this component is also a good option.
5. Tachometer
A failing engine speed sensor could be the cause of numerous problems in your car. It's an essential component of the Audi's transmission as it sends information to the ECU about how fast or slow the car's crankshaft is turning. When this sensor fails, it can affect the performance of the transmission as well as the rest of the car's components.
The G5 engine speed get more info sensor is located at the outside of the transmission just above the flywheel ring gear. It sends a signal directly to the ECU at pin T55/49, via an uncolored wire. The ECU then processes the signal to control fuel, timig, and boost and then transmitting it to the G5 Tachometer located in the instrument cluster. You can check the sensor for failure by examining the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79]) and between T6a/1 and check here the instrument cluster pin T26a/12. You should observe approximately 1000 ohms of resistance between these here two points. This is a standard part across the Audi 80 100 200, UrS and RS2 range from 1985 MC until here the 1997 UrS AAN and 1995 RS2 ADU so good ones might be availble in wrecking yards.