How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. This sensor is located on the edge of the transmission just above the flywheel ring 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
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 via an uncolored wire. The ECU utilizes this information to control the amount of fuel and boost. It also sends a signal to the G5 tachometer inside 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 reached TDC and also the position of the camshaft, so that it can activate 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, possibly indicating the chain is stretched or a jump link on the upper timing chain. However, the code won't be displayed on its own without additional information from other sensors (G4 and G40).
Testing can be a bit difficult since there are two pins for the connector and they serve different purposes however the best method to test it is by measuring resistance between the sensor and the ECU. It should read approximately 1000 ohms when the sensor is in full operation. If you're experiencing issues with this part, check for evidence 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 reduction in power. It was like the engine had run out of gas. Or my injectors weren't firing. Today, i pulled out the spark plugs, three were soaked with gazoline and the fourth one was dry. When I start the engine, there are no sparks, I put a piece of tissue on the top of each of the injector holes, the 3 drenched with gazoline leap out, however the 4th stay closed. I tested the ground connection on ECU pins 14/55,30/55 and 48/55 i get 0ohm. I assume that the problem is somewhere else.
I also tried to reset the PID with no success. The car will start when the G28 is unplugged and it runs perfectly when it is plugged in but it still is experiencing intermittent misfires at higher RPM. The coolant sensor (G62) even when unplugged, still shows an ice temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bars when the actual pressure is 0.
I'm not sure what to do. I feel like i've pretty much ruled everything else out. However, i'm afraid that i might have missed something. Let me know If you have any suggestions! TIA!
3. Fuel Pump
The fuel pump of here the g28 gets 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 find an extra in a wrecking shop or a parts store. Testing them is easy - put your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector's end up) and 2 click here (2nd from left on the black connector's side). They should be infinite Ohms.
4. ECU
Our 20vt turbo (3B, AAN, ABY and ADU) engines are equipped with an ECU that needs to know the position and speed of the crankshaft in order to make decisions regarding fuel injector timing etc. To accomplish this, it how to open audi car key utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you are experiencing issues with either one of these, the diagnostic scanner will show the codes that could trigger click here an engine shutdown.
The signs of a failed G28 sensor are an inaccurate rev counter for the gearbox, gears shifting quicker than normal and/or a misfire when in gear. If you have any of these issues it is click here likely your sensor is deteriorating and should be replaced. They are cheap and easy-to-find especially in the case of an Bosch sensor like ours. Alternately, GM's version this part is an excellent choice.
5. Tachometer
A damaged engine sensor could cause a variety of issues in your vehicle. It is a crucial part of your Audi's transmission, as it sends information to the ECU about how fast or slow the car's crankshaft is rotating. If this sensor fails, it can affect the performance of the transmission as well as the other car's components.
The G5 engine sensor is located near the edge of the transmission, over the flywheel ring. It sends a signal via a gray wire to the ECU pin T55/49. The ECU uses this signal to regulate fuel and boost, and also timig. It also sends it to the G5 Tachometer inside the instrument cluster. You can check the sensor for any failure by checking the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should see an average resistance of 1000 ohms between these two points. This is a typical component across the Audi 80, 100 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU so good parts could be found in wrecking yards.