25 Surprising Facts About Audi G28
25 Surprising Facts About Audi G28
Blog Article
How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. The sensor is situated on the edge of the transmission just above the flywheel ring gear. It sends a message to the ECU via the grey wire T55/49 and then to the tachometer on the instrument cluster.
1. Engine Speed Sensor
The grey wire is situated at the edges of the transmission, above the flywheel ring. The sensor transmits signals through the grey wire to pin T55/49. The ECU utilizes this information to regulate boost and fuel. It also sends a signal to the G5 tachometer inside the instrument cluster.
The sensor is used to connect the G40 Camshaft position Sensor. The ecu must know when the crankshaft is TDC and where the camshaft is located so that it can trigger spark and injectors accordingly.
If this sensor fails to function, the ECU will display an error code P00160. This indicates that the Crank Shaft is out of line with the Intake Camshaft. It could also indicate the possibility of a chain stretch or jumpy chain link in the upper chain of timing. The code will not appear without the additional information provided by other sensors (G4 or G40).
Testing can be a bit difficult since there are two connector pins and they have different functions but the best method of testing it is to measure the resistance between the sensor and the ECU. It should read around 1000 ohms when the sensor is at full operation. Look for signs of coolant, or oil in the connector bay if you have issues with this part.
2. Injectors
Yesterday, while accelerating at full speed from the highway paytoll, I experienced a big cut in power like the engine is out of gas or the injectors aren't firing at all. This morning i pull out the spark plugs, 3 were drenched with gazoline the fourth was dry. When I crank the engine, there are no sparks, i place a tissue on top of each injector hole and the 3 drenched with gazoline jump out but the 4th stays shut. I tested the ground connection on ECU pins 14/55, 30/55 and 48/55. I got zero ohm. I assume that the problem is in another location.
I also tried to reset the PID without success. The car can start if the G28 is not plugged in and it runs perfectly when it is plugged in, audi spare key but still has the intermittent misfire issue at higher RPM. The coolant sensor (G62), even when unplugged, still shows an ice temperature of -49c. Also, i noticed that the gauge for oil pressure in the cockpit shows 2 get more info bar when the actual pressure is 0.0 when i rev the engine.
I'm not certain what to do, as i feel i have pretty much eliminated everything else. I'm afraid i may have missed something. If anyone has any ideas please chime in! TIA!
3. Fuel Pump
The fuel pump in the g28 receives 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 locate an extra in a wrecking shop or a parts store. Test them out to do - just put your DMM in resistance mode and measure between pins 1 (with the bump on the connector's side up) and 2 (2nd from left on the black end of the connector). They should be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY and ADU) engines are equipped with an ECU that has to be aware of the speed and position of the crankshaft to make decisions about timing of the fuel injectors, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these goes bad you will get codes on the diagnostic scanner which could cause engine shut down.
The signs of a malfunctioning G28 sensor include an inaccurate rev counter for the gearbox, gears shifting quicker than normal and/or a misfire when you are in gear. If you are experiencing any of these problems, it is most likely that your sensor is going bad and should be replaced. The good news is they are very affordable and readily available, especially if you're looking at a Bosch unit which is what we have. Alternatively, GM's version of this part would be a good option.
5. Tachometer
A failing engine sensor could cause a variety of issues in your vehicle. It is a crucial part of the Audi's transmission because it communicates to the ECU about how fast or slow the vehicle's crankshaft is rotating. When this sensor fails, it will affect the performance of the transmission as well as the other car's components.
The G5 engine sensor is located at the edge of transmission, above the flywheel ring. It transmits signals via gray wire audi replacement car keys to ECU pin T55/49. The ECU uses this signal to regulate the amount of fuel and boost, as well as timig. It also transmits it to the G5 Tachometer located in the instrument cluster. You can check the sensor for failure by examining the continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should detect the resistance to be around audi replacement key 1000 ohms in these areas. This part is common across the Audi 80-100-200-RS2 model, ranging beginning with the 1985 MC and up to the 1997 UrS AN and the 1995 RS2 Du, so you might read more find them in wrecking yards.