"The Ultimate Cheat Sheet" On Audi G28
"The Ultimate Cheat Sheet" On Audi G28
Blog Article
How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. The sensor is located at the top of the transmission, above the flywheel ring 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
The grey wire is located on the edge of transmission, above the flywheel ring. This sensor sends a signal via the grey wire to pin T55/49. The ECU utilizes this information to regulate boost and fuel. It also sends signals to the G5 tachometer inside 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 to function, the ECU will display a P00160 error code. This indicates that the Crank Shaft is out of sync with the Intake Camshaft. It could also be a sign of the possibility of a chain stretch or jumped chain link in the upper chain. However, the code won't appear on its own without additional information from other sensors (G4 and G40).
Testing is a bit challenging because there are two connector pins, and they perform different functions but the best method to test it is by measuring resistance between the sensor and the ECU. It should read about 1000 ohms when the sensor is in full operation. If you are having problems with this component, look for evidence of oil or coolant in the connector bay.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at a high speed I noticed a significant drop in power. It was like the engine had run out of gas. Or, my injectors weren't firing. This morning i pull out the spark plugs, 3 were drenched in gazoline, the fourth one was dry. When I crank the engine, there are no sparks, I put a piece of tissue on the top of each of the injector holes, the 3 drenched with gazoline jump out but the 4th one stays closed. I tested the ground connection of ECU pins 14,30, and 48/55. I got zero ohm. So i assume the problem is somewhere else.
I also tried to reset the PID without success. The car can start if the G28 is unplugged and runs fine when it is connected but it still is experiencing intermittent misfires at higher RPM. The coolant sensor (G62), even when unplugged, still shows a temperature of -49c. Also, i noticed that the gauge for oil pressure in the cockpit is showing 2 bar when the actual pressure is 0.0 when I crank up the engine.
I'm not sure what to do. I feel like i've pretty much ruled everything else out. But new audi car key i'm worried that i might have missed something. If anyone has suggestions, please share them! TIA!
3. Fuel Pump
The fuel pump of the g28 gets a signal from the RPM sensor. The GM-style transmitter is identical to 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 in a local parts store. It is simple to read more test them - just switch your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump on the connector's edge facing up). They must be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY and ADU) engines have an ECU that must know the position and speed of the crankshaft in order to make a decision about fuel injector timing etc. To do this, it utilizes a new audi key Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you are experiencing issues with either of these sensors, the diagnostic scanner will show codes that could lead to an engine shutdown.
Some of the signs check here of a failed G28 sensor include an inaccurate rev counter in the gearbox, gears shifting click here 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. The good news is they are very cheap and easy to find, especially if you're looking at a Bosch model, like ours. Alternately, the GM version of this component is also a good choice.
5. Tachometer
A malfunctioning engine speed sensor could be the reason behind a slew of issues in your car. It is a crucial part of your Audi's transmission, since it relays information to the ECU about how fast or slow the vehicle's crankshaft is turning. When this sensor fails, it will affect the performance of the transmission and the other car's components.
The G5 engine speed sensor is situated on the edge of the transmission just above the flywheel ring gear and sends a signal 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 sends it on to the G5 tachometer inside the instrument cluster. You can test for sensor failure by examining the continuity of the sensor to the tachometer. Additionally, you can check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]) and between pin T6a/1 as well as pin T26a/12. There should be the resistance to be around 1000 ohms between these points. This is a common feature across the Audi 80-100-200-RS2 model, ranging beginning with the 1985 MC and up to the 1997 UrS AN and 1995 RS2 DU You may also find some good ones in wrecking yards.