5 Laws That Anyone Working In Audi G28 Should Be Aware Of
How to Replace an Audi a3 Spare Key G28 Engine Speed Sensor
In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. This sensor is situated near the transmission's edge over the flywheel gear. It transmits a signal to the ECU through the grey wire T55/49 and then to the tachometer located on the instrument cluster.
1. Engine Speed Sensor
The grey wire is situated on the edge of transmission, above the flywheel ring. The sensor sends an electrical signal through the grey wire to pin T55/49. The ECU uses this information to regulate the amount of fuel and boost. It also sends an indication to the G5 tachometer inside the instrument cluster.
The sensor is used to connect the G40 Camshaft position Sensor. The ecu must know when the crankshaft is TDC and where the camshaft is located so that it can start spark and injectors according to the situation.
If this sensor fails the ECU will throw an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are audi tt key fob not working in sync and could indicate the chain is stretched 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).
Testing is a bit challenging because there are two connector pins and they serve different purposes but the best method to test it is to measure resistance between the sensor and the ECU. If the sensor is operational, it should be reading approximately 1000 ohms. Check for signs of coolant or oil in the connector bay if you have issues with this part.
2. Injectors
Yesterday, while accelerating from the highway paytoll at maximum speed I noticed a significant decrease in power. It was like the engine had run out of gas. Or, my injectors weren't firing. I pulled out the spark plugs this morning, 3 were soaked in gasoline, and the fourth was dry. I put tissue over each hole in the injector and when i turn the engine on without sparks, the 3 with gazoline jump right out. The fourth one remains shut. I inspected the ground connection on ECU pins 14/55,30/55 and 48/55 i get zero ohm. I assume that the problem is elsewhere.
I also tried to reset PID without success. The car will start if the G28 is unplugged and it runs perfectly when it is plugged in, but still has intermittent misfire issues at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature value of that is -49c even after unplugging it. I also noticed that the gauge replacement key for audi oil pressure in the cockpit is showing 2 bar while the actual pressure is 0.0 when i rev the engine.
I don't know what to do. I think I've eliminated everything else. I'm afraid i may have missed something. Let me know should you have any suggestions! 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 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 wrecking yard or in a local parts store. It is easy to test them - just put your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump on the connector's edge facing upwards). They should be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY, and ADU) engines have an ECU that must know the position and speed of the crankshaft to make decisions about timing of the fuel injectors, etc. To do this, it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these goes wrong, you will receive codes on the diagnostic scanner that can cause the engine to shut down.
A damaged G28 sensor could result in an inaccurate gearbox speed counter, a gearbox that shifts more quickly than normal, and/or a misfire while in gear. It is likely that the sensor is failing and needs to be replaced if you experience any of these symptoms. The good news is they are very affordable and easily accessible, especially if you're looking at the Bosch unit like ours. You can also choose the GM version of this component is also a great option.
5. Tachometer
A damaged engine sensor could cause a myriad of issues in your vehicle. It's an essential component of the transmission in your audi replacement key cost, as it transmits information to the ECU regarding how fast or slow the engine of the audi car key replacement is turning. This sensor could cause the transmission to fail and other components of the car to be affected.
The G5 engine speed sensor is situated on the outside of the transmission, above the flywheel ring gear and transmits a signal to the ECU at pin T55/49 via a grey wire. The ECU utilizes this signal to control the flow of fuel and boost and also timig. It also transmits it to the G5 Tachometer inside the instrument cluster. You can determine if the sensor is in failure by examining the continuity of the sensor to the tachometer. You can also examine the continuity between pins T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]) and between pin T6a/1 as well as pin T26a/12. You should detect a resistance of approximately 1000 ohms between these points. This is a standard component across the audi a3 spare key 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.