20 Inspirational Quotes About Audi G28
How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. programming audi key TheKeyLab is situated at the top of the transmission above the flywheel ring gear. It sends a signal to the ECU via an uncolored wire (T55/49) which is then sent to the tachometer located 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 signals to ECU pin T55/49 via an uncolored wire. The ECU uses this information to regulate boost and fuel. It also sends an indication to the G5 tachometer in the instrument cluster.
The sensor serves as a reference point to connect with the G40 Camshaft Position Sensor. The ecu must be aware when the crankshaft is TDC and where the camshaft is so it can trigger spark and injectors accordingly.
If this sensor fails, the ECU will show an error code P00160 which indicates that the Crank Shaft and Intake Camshaft aren't in sync and could indicate the chain stretching or a jump link on the upper timing chain. The code won't show without the additional information supplied by other sensors (G4 or G40).
Testing is a bit tricky as there are two different connector pins and they serve different purposes but the best method to test it is by measuring resistance between the sensor and the ECU. If the sensor is functional, it should read approximately 1000 ohms. If you are having problems with this sensor, look for signs of oil or coolant in the connector bay.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at maximum speed I noticed a significant drop in power. It was like the engine had run out of gas. Or, my injectors were not firing. This morning i pull out the spark plugs, three were soaked with gazoline and the 4th one was dry. I placed a tissue over each injector hole and when i start the engine without sparks, the three that have gazoline pop right out. The fourth one remains closed. I tested the ground connection on ECU pins 14/55, 30/55 and 48/55. i get zero ohm. Therefore, i think the issue is elsewhere.
I also tried to reset PID without success. The car can start when the G28 is unplugged and it runs perfectly when it is connected however it has intermittent misfire issues at higher RPM. The coolant sensor (G62), even when unplugged, still shows a temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is 0.
I don't know what to do. I believe that I've eliminated everything else. I'm concerned that i may have missed something. If anyone has any suggestions, please chime in! 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 similar to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily find the spare in a salvage shop or a parts store. It is simple to test them - just put your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump on the connector's edge facing up). They must be infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY ADU) engines must know the position and speed of the crankshaft to make decisions regarding timing of fuel injectors, etc. It utilizes 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 lead to an engine shut down.
A failing G28 sensor can cause an inaccurate speed counter for the gearbox and a gearbox which shifts more quickly than normal, or an unfire when in gear. It is likely that your sensor is failing and requires to be replaced if you experience any of these symptoms. They are cheap and easy-to-find especially if they're an Bosch unit like ours. Alternatively, the GM version of this part is also a good choice.
5. Tachometer
A malfunctioning engine sensor can cause a number of problems in your car. It's a vital component of the Audi's transmission as it sends information to the ECU about how fast or slow the vehicle's crankshaft is rotating. If this sensor fails, it can disrupt the performance of the transmission, as well as the rest of the car's components.
The G5 engine sensor is located near the edge of the transmission, over the flywheel ring. It transmits an electrical signal through gray wire to ECU pin T55/49. The ECU utilizes this signal to control the amount of fuel and boost, as well as timig. It also relays it to the G5 Tachometer in instrument cluster. You can check for sensor failure by examining the continuity from the sensor to the tachometer. You can also check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]), and between pin T6a/1 and pin T26a/12. You should see approximately 1000 ohms resistance between those two pins. This is a common part across the Audi 80, 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU so good parts could be found in wrecking yards.