The Most Pervasive Issues With Audi G28
The Most Pervasive Issues With Audi G28
Blog Article
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, above the flywheel gear. It transmits a signal to the ECU via the grey wire (T55/49) and then to the tachometer located in the instrument cluster.
1. Engine Speed Sensor
Located on the edge of the transmission just above the flywheel ring gear the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 via a grey wire. The ECU then utilizes this information to regulate the flow of fuel, timig and boost. It also sends signals to the G5 Tachometer located in the instrument cluster.
The sensor is used as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must be aware when the crankshaft is TDC and the location of the camshaft so it can trigger spark and injectors in the right way.
If this sensor fails the ECU will throw the P00160 error, which means the Crank Shaft and Intake Camshaft are not in sync, possibly indicating chain stretch or a jumped link on the upper chain of timing. The code won't appear without the additional information provided by other sensors (G4 or G40).
It's a bit tricky to test as there are several pins on the connector, and each has its own functions. The best way to do it is to measure the resistance between the ECU and the sensor. If the sensor is operational, it should be reading about 1000 ohms. Examine for signs of coolant or oil in the connector bay if you are experiencing issues with this part.
2. Injectors
Yesterday, when i was accelerating to the fullest speed from highway paytoll i had an abrupt drop in power like the engine is running out of gas or injectors are not firing any more. In the morning, i removed the spark plugs, 3 were drenched in gazoline, the 4th one was dry. I put a piece of tissue over each injector hole, and when I turn the engine on without sparks, the 3 with gazoline jump 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. I think the issue is somewhere else.
I also tried to reset the advanced key audi PID but with no luck. The car will start when the G28 is unplugged, and 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 of that is -49c even after unplugging it. 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, as i think i've pretty much ruled out everything else. I'm afraid i may have missed something. Let me know should you have any suggestions! TIA!
3. Fuel Pump
The audi key programming near me 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 locate a spare in a wrecking shop or a parts store. Testing them is easy by replacement audi car key putting your DMM in resistance mode and measure between pins 1 (with the bump on the connector's side up) and 2 (2nd from the left on the black connector's end). They must be infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY) engines must know the position and speed the crankshaft in order to make a decision about timing of fuel injectors, etc. In order to do here this it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these go bad you will get codes on the diagnostic scanner which could cause engine shut down.
A damaged G28 sensor can cause an inaccurate speed counter for the gearbox or a gearbox that shifts more quickly than normal, or a misfire in gear. It is possible that your sensor is failing and needs to be replaced if you notice any of these symptoms. They're inexpensive and easy to locate particularly if they're a Bosch unit like ours. Alternately, GM's version this part is an option.
5. Tachometer
A malfunctioning engine sensor can cause a variety of issues in your vehicle. It's a crucial component of the transmission of your Audi, as it transmits information to the ECU regarding how fast or slow the engine of the car is spinning. This sensor can cause the transmission to fail and other components of the car to be affected.
The G5 engine speed sensor is located on the outside of the transmission, audi advanced key above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49 through a grey wire. The ECU then processes this signal to regulate fuel, timig, and boost, and also transmitting it to the G5 Tachometer located in the instrument cluster. You can test the sensor for failure by examining the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. It should show approximately 1000 ohms of resistance between these two points. This is a typical part across the Audi 80, 100 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU. Good ones might be availble in wrecking yards.