Ten Situations In Which You ll Want To Be Aware Of Audi G28
How to Replace an Audi A1 keys G28 Engine Speed Sensor
In this video, Charles the Humble Mechanic demonstrates 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 a grey wire T55/49, then to the tachometer located on the instrument cluster.
1. Engine Speed Sensor
It is located on the outside of the transmission, above the flywheel ring gear G28 Engine Speed Sensor sends a signal to ECU pin T55/49 through an uncolored wire. The ECU uses this information to control the amount of fuel and boost. It also sends signals to the G5 tachometer inside the instrument cluster.
The sensor audi A4 key replacement is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu must know 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 show the P00160 error, which means the Crank Shaft and Intake Camshaft are out of sync and could indicate the chain stretching or a jump link on the upper chain of timing. The code won't show without the additional information provided by other sensors (G4 or nearby G40).
Testing can be a bit difficult as there are two different connector pins and they serve different purposes however the best method to test it is by measuring resistance between the sensor and the ECU. It should read approximately 1000 ohms when the sensor is operating at its maximum. Examine for signs of coolant, or oil in the connector bay if there are problems with this part.
2. Injectors
Yesterday, while accelerating at full speed from the highway paytoll i had massive power loss as if the engine was running out of gas or the injectors are not firing any more. I took out the spark plugs this morning, 3 were drenched 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 ones that have gazoline pop right out. The 4th 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 elsewhere.
I also tried to reset the PID without success. The car will start when the G28 is unplugged, and it works fine when the G28 plugged in. However the intermittent misfire issue still occurs at higher RPM. The coolant temperature sensor (G62) shows the wrong temperature value of -49c even when i unplug it. Also i noticed that the oil pressure gauge in the cockpit is showing 2 bar, whereas the actual pressure is 0.0 if i crank up the engine.
I'm not sure what to do, as i feel i have pretty much eliminated everything else. However, i'm afraid that I may have missed something. If anyone has suggestions, please let me know! TIA!
3. Fuel Pump
The fuel pump in the g28 can be activated by a signal from the RPM sensor. The GM-style transmitter functions similarly to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. You can easily find a spare in a wrecking shop or parts store. It is simple to test them to do - just put your DMM in resistance mode and measure between pins 1 (with the bump on the connector's end up) and 2 (2nd from left on the black connector's side). They should be infinite ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY) engines must know both the speed and position of the crankshaft to determine timing of fuel injectors, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you have a problem with either of these, the diagnostic scanner will show codes that could lead to the engine shutting down.
Some of the symptoms of a failing G28 sensor include an inaccurate rev counter in the gearbox the gears are shifting faster than normal and/or misfiring when you are in gear. It is likely that the sensor is failing and requires to be replaced if you encounter any of these signs. The good news is they are very cheap and readily available particularly when you're looking at a Bosch unit like ours. Alternately, GM's version this part is a good option.
5. Tachometer
A faulty engine speed sensor could be the cause of many issues with your vehicle. It's an essential component of the transmission of your Audi Q7 Key, as it transmits information to the ECU regarding how fast or slow the car's engine is turning. When this sensor fails, it could disrupt the performance of the transmission as well as the other car's components.
The G5 engine speed sensor is located on the outside of the transmission just above the flywheel ring gear. It sends a signal directly to the ECU at pin T55/49 through an uncolored wire. The ECU utilizes this signal to control fuel and boost, and Audi Connect key also timig. It also relays it to the G5 Tachometer in instrument cluster. You can check the sensor for failure by checking continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should detect an average resistance of 1000 ohms in these areas. This is a typical part across the audi car key case 80, 100, 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU, so the best parts could be found in wrecking yards.