10 Best Mobile Apps For Audi G28
How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. The sensor is situated near the edges of the transmission, above the flywheel ring gear. It transmits a signal the ECU via an uncolored 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 a signal to ECU pin T55/49 using a grey wire. The ECU then utilizes this information to regulate fuel, timig and boost. It also sends an indication to the G5 Tachometer within the instrument cluster.
The sensor is used as a reference for comparing with the G40 Camshaft Position Sensor. The ecu must be aware of when the crankshaft has reached TDC, and the location of the camshaft in order to activate the spark and injectors.
If this sensor fails when it fails, the ECU will display a P00160 error message. This means that the Crank Shaft is not in alignment with the Intake Camshaft. It could also indicate a chain stretch or a jumped chain link in the upper chain of timing. However the code will not be displayed on its own without additional information from other sensors (G4 and G40).
Testing is a bit challenging since there are two connector pins and they perform different functions but the best method to test it is to measure resistance between the sensor and the ECU. It should read around 1000 ohms if the sensor is operating at its maximum. If you're having issues with this sensor, look for evidence of oil or coolant in the connector bay.
2. Injectors
Yesterday, while accelerating from the highway paytoll at a high speed, i noticed a huge drop in power. It was as if 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 fourth one was dry. I placed a tissue over each injector hole, and when i start the engine with no sparks, the 3 with gazoline jump out. The fourth one remains shut. I tried to test the ground connections of ECU pins 14,30, and 48/55. I got zero ohm. I assume that the problem is somewhere else.
I also tried to reset the PID without success. The car can start when the G28 is disconnected 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 it is unplugged, shows an ice temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bar but the actual pressure is zero.
I'm not sure what to do. I believe that I've ruled everything else out. But i'm worried that I might have missed something. If anyone has suggestions, please chime in! TIA!
3. Fuel Pump
The fuel pump on the g28 is activated by a signal sent by the RPM sensor. The GM-style sender is identical to the G4 and both are used in the 80 100, 200, UrS and RS2 cars so you can easily find one at a wrecking yard or in a local parts store. It is easy to test them: simply put your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector's 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 has to be aware of the speed and position of the crankshaft to make decisions about timing of the fuel injectors, etc. audi lost key replacement makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these go badly, you will see codes on the diagnostic scanner that can cause the engine to shut down.
A malfunctioning G28 sensor could result in an inaccurate speed counter for your gearbox and a gearbox which shifts faster than normal, or an unfire when in the gear. It is possible that your sensor is failing and needs to be replaced if you experience any of these symptoms. The good news is that they are very cheap and easy to find, especially in the case of a Bosch model, which is what we have. Alternately, GM's version this part is a good option.
5. Tachometer
A failing engine speed sensor could be a cause for numerous issues in your car. It's an essential component of the transmission of your Audi because it relays information to the ECU on how fast or slow the engine of the car is spinning. This sensor could cause the transmission to malfunction and other components of the car to be affected.
The G5 engine sensor is located at the edge of the transmission, just above the flywheel ring. It sends a signal via gray wire to ECU pin T55/49. The ECU uses this signal to control the flow of fuel and boost and also to timigrate. It also transmits it to the G5 Tachometer inside 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 via pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. It should show approximately 1000 ohms resistance between those points. This is a standard component across the Audi 80, 100, 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU, so the best ones could be available in wrecking yards.