Audi G28: The Good, The Bad, And The Ugly
Audi G28: The Good, The Bad, And The Ugly
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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. This sensor is situated at the edge of transmission just above the flywheel gear. It transmits a signal to the ECU via an uncolored wire (T55/49) which is then sent to the tachometer within the instrument cluster.
1. Engine Speed Sensor
Located on the edge of the transmission above the flywheel ring gear the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 via an uncolored wire. The ECU then uses this information to control the flow of fuel, timig and boost. It also sends a signal to the G5 tachometer inside the instrument cluster.
The sensor serves as a reference point to connect with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft is TDC and where the camshaft is located so that it can activate spark and injectors in the right way.
If this sensor fails the ECU will show a P00160 code which means the Crank Shaft and Intake Camshaft are out of sync, possibly indicating the chain is stretched or a jump link on the upper timing chain. However, the code won't appear on its own without additional information from other sensors (G4 and G40).
Testing can be a bit difficult since there are two connector pins, and they perform different functions however the best method of testing it is to measure the resistance between the sensor and the ECU. If the sensor is operational, it should be reading approximately 1000 ohms. If you're having issues with this part, check for signs of coolant or oil in the connector bay.
2. Injectors
Yesterday, when i was accelerating to the fullest speed from highway paytoll, I experienced massive power loss like the engine is out of gas or injectors aren't firing any more. This morning i pull out the spark plugs, three were soaked with gazoline and the fourth one was dry. I put tissue over each injector hole, and when I turn the engine on without sparks, the 3 with gazoline jump right out. The 4th one stays closed. I tested the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I got 0ohm. I assume that the problem is elsewhere.
I also tried to reset the PID with no success. The car will start when the G28 is disconnected, but it runs fine with the G28 plugged in. However the intermittent misfire issue persists at higher RPM. The coolant temperature sensor (G62) shows the wrong temperature value of -49c even when i unplug it. replace audi key I also noticed that the oil gauge in the cockpit shows 2 bars while the actual pressure is 0.
I'm not sure what to do, i believe that i've completely ruled out all other possibilities. But i am afraid I might have missed something. Please let me know If you have any audi lost key suggestions! TIA!
3. Fuel Pump
The fuel pump on the g28 is activated by a signal from the RPM sensor. The GM-style transmitter is similar to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. You can easily find a spare in a wrecking shop or parts store. Test them out - put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector end up) and 2 (2nd from the left on the black connector's side). They should be infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY) engines requires to know the position and speed the crankshaft to determine fuel injector timing, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If either of these sensors go wrong, you will receive codes on the diagnostic scanner which can lead to engine shutdown.
Some of the signs of a malfunctioning G28 sensor include an inaccurate gearbox rev counter, gears shifting quicker than normal, and/or a misfire when you are in gear. If you have any of these issues it is likely your sensor is going bad and needs replacing. They are cheap and easy-to-find, especially in the case of an Bosch model like ours. If you prefer, GM's version of this part would be a good option.
5. Tachometer
A damaged engine sensor could cause a myriad of issues in your car. It's an essential component of the transmission in your Audi since it sends information to the ECU about how fast or slowly the engine is turning. This sensor could cause audi a4 car key replacement the transmission to malfunction and other components in the car to be affected.
The G5 engine sensor is located at the edge of the transmission, just above the flywheel ring. It sends signals via an uncolored 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 located in the instrument cluster. You can check for sensor failure by examining the continuity of the sensor to the tachometer. Additionally, you can verify continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]), and between pin T6a/1 and pin T26a/12. You should detect a resistance of approximately 1000 ohms lost audi key between these two points. This is a common feature across the Audi 80-100-200-RS2 model, ranging check here from the 1985 MC up to the 1997 UrS An and 1995 RS2 DU So, you may find some good ones in wrecking yards.