How to Replace an Audi G28 Engine Speed Sensor
In this video Charles the Humble Mechanic shows 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 to the ECU via a grey wire T55/49, 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 an electrical signal to ECU pin T55/49 using the grey wire. The ECU utilizes this information to control fuel and boost. It also sends signals to the G5 tachometer inside the instrument cluster.
The sensor is used to link with the G40 Camshaft position Sensor. The ecu must know when the crankshaft reached TDC and also the location of the camshaft in order to activate the spark and injectors.
If this sensor fails, the ECU will display a P00160 error message. This indicates that the Crank Shaft is out of sync with the Intake Camshaft. It could also indicate a chain stretch or a jump in the chain link of the upper timing chain. However, the error code won't appear on its own, without additional information from other sensors (G4 and G40).
Testing is a bit challenging since there are two pins for the connector and they perform different functions however the best way to test it is to measure resistance between the sensor and the ECU. It should read approximately 1000 ohms if the sensor is operating at its maximum. Look for signs of coolant or oil in the connector bay if you are experiencing issues with this component.
2. audi a4 key replacement , when i was accelerating to the fullest speed from highway paytoll i had massive power loss like the engine is running out of gas or the injectors are not firing anymore. Today, i pulled out the spark plugs. Three were soaked with gazoline and the 4th one was dry. I placed a tissue over each hole in the injector and when I start the engine without sparks, the three with gazoline jump out. The 4th one stays shut. I checked the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I got zero ohm. I assume that the problem is elsewhere.
audi a3 key replacement tried to reset the PID but with no luck. The car will start when the G28 is unplugged, and it works fine when the G28 connected. However, the intermittent misfire problem persists 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 bar but the actual pressure is zero.
I'm not sure what to do, as i think i've pretty much ruled out everything else. However, i'm afraid that I might have missed something. Please let me know If you have any suggestions! TIA!
3. Fuel Pump
The fuel pump in the g28 can be activated by a signal sent from the RPM sensor. audi a3 key replacement near me -style sensor is the same as the G4 and both function in the 80, 100 200, UrS and RS2 cars which is why you can easily locate one at a salvage yard or at a parts store. It is easy to test them - just switch your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump at the connector's end facing up). They should be infinite ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY ADU) engines must be aware of the position and speed of the crankshaft to determine fuel injector timing, etc. To accomplish 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, the diagnostic scanner will show codes that could lead to the engine shutting down.
Some of the signs of a failing G28 sensor include an inaccurate rev counter for the gearbox the gears are shifting faster than normal, and/or a misfire when you are in gear. It is possible that the sensor is failing and needs to be replaced if you notice any of these symptoms. The good news is they are very cheap and easily accessible, especially when you're looking at the Bosch unit like ours. Alternately, the GM version of this component is also a good option.
5. Tachometer
A faulty engine speed sensor could be a cause for a slew of issues with your vehicle. It is an important part of the transmission in your Audi, as it transmits information to the ECU regarding how fast or slowly the engine of the car is turning. This sensor could cause the transmission to fail and other components of the car to be affected.
The G5 engine sensor is located at the edge of the transmission, over the flywheel ring. It transmits signals via an uncolored wire to the ECU pin T55/49. The ECU is then able to process the signal to control fuel, timig and boost, and also transmitting it to the G5 Tachometer located in the instrument cluster. You can check the sensor for failure by checking continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should see an average resistance of 1000 ohms between these points. This is a common feature across the Audi 80-100-200-RS2 range, from the 1985 MC all the way up to the 1997 UrS AN and the 1995 RS2 Du So, you may find some good ones in wrecking yards.