7 Small Changes That Will Make The Biggest Difference In Your Audi G28
How to Replace an Audi G28 Engine Speed Sensor
In this video Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is situated on the edge of the transmission above the flywheel ring gear. It sends a signal to the ECU via the grey 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 an electrical signal to ECU pin T55/49 using an uncolored wire. The ECU then uses this information to control the boost, fuel, and timig. It also sends signals to the G5 Tachometer located in the instrument cluster.
The sensor serves as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft is TDC and where the camshaft is so it can start spark and injectors according to the situation.
If this sensor fails the ECU will throw the P00160 error, which means the Crank Shaft and Intake Camshaft are not in sync and could indicate the chain stretching or a jump link on the upper timing chain. The code won't show without the additional information supplied by other sensors (G4 or G40).
It is a little tricky to test because there are various connector pins, 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 functional, it should read approximately 1000 ohms. Check for evidence of coolant or oil in the connector bay if you have problems with this part.
2. Injectors
Yesterday, while accelerating from the highway paytoll at a high speed I noticed a massive reduction in power. audi advanced key was as if the engine was running out of gas. Or my injectors were not firing. This morning i pull out the spark plugs, 3 were soaked with gazoline and 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 hole in the injector and the 3 drenched with gazoline pop out, but the 4th stay closed. I checked the ground connection on ECU pins 14/55,30/55 and 48/55 I get zero Ohm. I assume that the problem is in another location.
I also tried to reset PID without success. The car can start if the G28 is disconnected and it runs perfectly when it is plugged in however it is experiencing intermittent misfires at higher RPM. The temperature sensor for the coolant (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 bar when the actual pressure is 0.
I'm not certain what to do, as i feel i have pretty much completely ruled out all other possibilities. I'm afraid i may have missed something. Please let me know if you have any ideas! TIA!
3. Fuel Pump
The fuel pump in the g28 can be activated by a signal by the RPM sensor. The GM-style transmitter is identical to the G4 and both are used in the 80 100 200, UrS and RS2 cars which is why you can easily locate one at a junkyard or from a parts store. Testing them is easy 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 end). They must be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY and ADU) engines have an ECU that must be aware of the speed and position of the crankshaft in order to make decisions about timing of the fuel injector, for example. To do this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you encounter a problem with either of these, the diagnostic scanner will display the codes that could trigger an engine shutdown.
A malfunctioning G28 sensor could cause an inaccurate gearbox speed counter or a gearbox that shifts more quickly than normal, or an unfire when in gear. It is probable that the sensor is failing and needs to be replaced if you encounter any of these signs. They're cheap and easy to find, especially if they're an Bosch sensor like ours. Alternately, the GM version of this component is also a good choice.
5. Tachometer
A damaged engine sensor could cause a myriad of issues in your vehicle. It's a vital component of your Audi's transmission, because it communicates to the ECU about how fast or slow the vehicle's crankshaft is spinning. This sensor can cause the transmission to fail and other components in the car to be affected.
The G5 engine speed sensor is located at the edge 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 is then able to process the signal to control fuel, timig and boost and then sends it on to the G5 Tachometer located in the instrument cluster. You can check for sensor failure by examining the continuity from the sensor to the tachometer. Additionally, you can examine the continuity between pins T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]) and between pin T6a/1 as well as pin T26a/12. There should be an average resistance of 1000 ohms in these areas. audi key replacement is common across the Audi 80-100-200-RS2 series, starting from the 1985 MC all the way up to the 1997 UrS An and 1995 RS2 Du You may also find some good ones in wrecking yards.