Audi G28: 10 Things I Wish I'd Known Earlier
Audi G28: 10 Things I Wish I'd Known Earlier
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 located near the transmission's edge just above the flywheel gear. It transmits a signal to the ECU via the grey wire (T55/49) which is then sent to the tachometer in the instrument cluster.
1. Engine Speed Sensor
The sensor is located at the edge of the transmission, above the flywheel ring gear, the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 via the grey wire. The ECU then uses this information to control the flow of fuel, timig and boost. It also sends an alert to the G5 Tachometer in instrument cluster.
The sensor is used to link the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft has reached TDC and also the position of the camshaft, to trigger the spark and injectors.
If this sensor fails the ECU will show an error code P00160 which indicates that the Crank Shaft and Intake Camshaft aren't in sync, possibly indicating the chain is stretched or a jump link on the upper timing chain. However, the code won't appear on its own, without additional information from other sensors (G4 and G40).
Testing is a bit challenging since there are two pins for the connector and they have different functions but the most effective method of testing it is to measure the resistance between the sensor and the ECU. When the sensor is operational, it should be reading about 1000 ohms. If you're having issues with this part, check for evidence of coolant or oil in the connector bay.
2. Injectors
Yesterday, when accelerating from highway paytoll at full speed I noticed a massive decrease in power. It was like the engine had run out of gas. Or, my injectors were not firing. Today, i pulled out the spark plugs. Three were drenched in gazoline, the fourth one was dry. I put a piece of tissue over each injector hole and when i start the engine with no sparks, the three that have gazoline pop right out. The 4th one remains shut. I tested the ground connection on ECU pins 14/55,30/55 and 48/55 i get zero ohm. I'm assuming that the issue is in another location.
I also tried to reset the PID without success. The car is able to start when the G28 is not plugged in and is running fine when it is connected but it still is here experiencing intermittent website misfires at higher RPM. The coolant temperature sensor (G62) shows the wrong temp value that is -49c even after unplugging it. I also noticed that the oil gauge in the cockpit shows 2 bars when the actual pressure is zero.
I'm not sure what to do, as i think i've pretty much ruled out everything else. I'm concerned that i may have missed something. If anyone has any ideas please share them! TIA!
3. Fuel Pump
The fuel pump in the g28 receives a signal from the RPM sensor. The GM-style transmitter is identical to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. You can easily find a spare in a wrecking shop or a parts store. Test them out - put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's side up) and 2 (2nd from the left on the black connector's end). They should be infinite Ohms.
4. ECU
Our 20vt turbo (3B, AAN, ABY and ADU) engines are equipped with an ECU that must be aware website of the speed and position of the crankshaft in order to make a decision about timing of the fuel injector, for example. In order to do this it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you encounter a problem with either of these, the diagnostic scanner check here will display codes that could cause an engine shutdown.
The signs of a failing G28 sensor are an inaccurate rev counter for the gearbox, gears shifting quicker than normal and/or a misfire when in gear. If you are experiencing any of these issues it is likely your sensor is failing and needs replacing. The good news is they are quite affordable and easy to find, especially when you're looking at the Bosch model, which is what ours are. You can also choose the GM version of this component is also a great option.
5. Tachometer
A damaged engine sensor could cause a myriad of issues within your vehicle. It is an important part of the transmission of your Audi because it relays information to the ECU on how fast or slow the 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 the transmission, just above the flywheel ring. It transmits a signal via an uncolored wire to the ECU pin T55/49. The ECU uses this signal to regulate the flow of fuel and boost as well as timig. It also relays it to the G5 Tachometer in instrument cluster. You can determine if the how much is a replacement audi key sensor is in failure by examining the continuity of the sensor to the tachometer. Also, you can examine the continuity between pins 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. You should detect the resistance to be around 1000 ohms in these areas. This is a common feature across the Audi 80-100-200-RS2 model, ranging from the 1985 MC up to the 1997 UrS AN and 1995 RS2 DU, so you might find good ones in wrecking yards.