It's The Ugly Truth About Audi G28
It's The Ugly Truth About Audi G28
Blog Article
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. This sensor is situated on the outside of the transmission, above the flywheel gear. It sends a message to the ECU through the grey wire T55/49 and then to the tachometer on the instrument cluster.
1. Engine Speed Sensor
It is located on the outside of the transmission just above the flywheel ring gear G28 Engine Speed Sensor sends signals to ECU pin T55/49 using a grey wire. The ECU then utilizes this information to regulate the boost, fuel, and timig. It also sends an indication to the G5 Tachometer in instrument cluster.
The sensor is used to connect the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft is TDC and where the camshaft is located so that it can activate spark and injectors according to the situation.
If this sensor fails, the ECU will throw a P00160 code which means the Crank Shaft and Intake Camshaft aren't in sync, possibly indicating the chain stretching or a jump link on the upper chain of timing. However, the error code won't appear on its own without additional information from other sensors (G4 and G40).
It can be a bit difficult to test because there are several connector pins, and each one has different functions. The most effective method to test it is by measuring the resistance between the ECU and the sensor. It should read around 1000 ohms when the sensor is at full operation. If you're having issues with this component, look for evidence of oil or coolant in the connector bay.
2. Injectors
Yesterday accelerating full speed from highway paytoll, I experienced a big cut in power as if the engine was running out of gas or the injectors aren't firing at all. I pulled out the spark plugs this morning, three were soaked in gasoline, and the 4th was dry. When I start 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 leap out, however the 4th one stays closed. I checked the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ i get 0ohm. So i assume the problem is somewhere else.
I also tried to reset the PID without success. The car will start when the G28 is disconnected and is running fine when it is connected, but still is experiencing intermittent misfires at higher RPM. The temperature sensor for coolant (G62) shows the wrong temp value -49c, even here if I unplug it. I also noticed that the oil pressure gauge in the cockpit is showing 2 bar while the actual pressure is 0.0 if i crank up the engine.
I'm not certain what to do, as i think i've pretty much ruled out everything else. But i'm worried that I might have missed click here something. Please let me know should you have any suggestions! TIA!
3. Fuel Pump
The fuel pump of the g28 receives a signal from 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 an extra in a wrecking shop or a parts store. It is simple to test them: simply put your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump at the connector end get more info facing up). They should be infinite ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY and ADU) engines have an ECU that must know the speed and position of the crankshaft in order to make decisions regarding fuel injector timing 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 can lead to engine shutdown.
A failing G28 sensor can cause an inaccurate speed counter for here your gearbox and a gearbox which shifts faster than normal, or a misfire in gear. If you have any of these issues, it is likely that your sensor is deteriorating and should be replaced. They're inexpensive and easy to locate especially when they're an Bosch unit like ours. Alternately, the GM version of this unit is also a great option.
5. Tachometer
A malfunctioning engine speed sensor could be a cause for a slew of problems in your car. It's an essential component of the transmission of your Audi since it sends information to the ECU on how fast or slowly the car's engine is spinning. This sensor could cause the transmission to fail and other components in the car to be affected.
The G5 engine sensor is located at the edge of transmission, above the flywheel ring. It sends signals via gray wire to ECU pin T55/49. The ECU utilizes this signal to regulate the amount of fuel and boost, and also to timigrate. It also sends it to the G5 Tachometer in instrument cluster. You can test for sensor failure by examining the continuity from the sensor to the tachometer. You can also verify continuity between pin 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. It should show approximately 1000 more info ohms resistance between those two pins. This part is common across the Audi 80-100-200-RS2 model, ranging 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.