How To Outsmart Your Boss On Audi G28
How To Outsmart Your Boss On Audi G28
Blog Article
How to Replace an Audi G28 Engine Speed Sensor
In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. This sensor is located at the top of the transmission just above the flywheel ring gear. It sends a message to the ECU through a grey wire T55/49, then to the tachometer located on 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 signals to ECU pin T55/49 using a grey wire. The ECU then uses this information to control the boost, fuel, and timig. It also sends a signal to the G5 tachometer in the instrument cluster.
The sensor is used as a reference to correlate with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft has reached TDC and also the position of the camshaft, in order to activate the spark and injectors.
If this sensor fails, the ECU will display an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are out of sync and possibly indicating the chain stretching or a jump link on the upper timing chain. 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 pins on the connector and they all have different functions. The most effective method to test it is to measure the resistance between the ECU and the sensor. It should read around 1000 ohms when it is operating at its maximum. Examine for evidence of coolant or oil in the connector bay if you have issues with this component.
2. Injectors
Yesterday, while accelerating from the highway paytoll at full speed I noticed a significant drop in power. It was like the engine was running out of gas. Or my injectors weren't firing. In the morning, i removed the spark plugs, three were drenched with gazoline the 4th one was dry. When I crank the engine, there are no sparks, i place a tissue on the top of each hole in the injector, the 3 drenched with gazoline jump out but the 4th stays closed. I inspected the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I got zero ohm. I'm assuming that the issue is elsewhere.
I also tried to reset PID without success. The car is able to start when the G28 is not plugged in and runs fine when it is connected, but still has the intermittent misfire issue at higher RPM. The coolant temperature sensor (G62) shows the wrong temperature of -49c even when i unplug it. I also noticed that the oil gauge in here the cockpit shows 2 bar while the actual pressure is 0.
I'm not certain what to do, but i feel i have pretty much eliminated everything else. I'm worried that i might have missed something. Please let me know If you have any suggestions! TIA!
3. Fuel Pump
The fuel pump of the g28 receives a signal from the RPM sensor. The GM-style sender is the same as the G4 and both function in the 80 100, 200, UrS and RS2 cars which is why you can easily locate one at a junkyard or at a parts store. It is simple to test them - just switch your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump on the connector's edge facing up). They should be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY, and ADU) engines have an ECU that needs to know the speed and position of the crankshaft to make a decision about timing of the fuel injector, for example. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you are experiencing issues with either of these sensors, the diagnostic scanner will display codes that could cause an engine shut down.
A damaged G28 sensor could result in an inaccurate speed counter for your gearbox, a gearbox that shifts faster than normal, and/or an unfire when in gear. It is likely that your sensor is failing and needs to be replaced if you encounter any of these symptoms. They're inexpensive and easy to locate especially if they're a check here Bosch model like ours. Alternately, GM's version this part would be a good option.
5. Tachometer
A damaged engine sensor could cause a number of problems in your vehicle. It's a crucial component of the transmission of your Audi, as it transmits information to the ECU about how fast or slow the engine is turning. If this sensor fails, it can cause problems for the transmission and the rest of the 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 via a grey wire. The ECU then processes this signal to regulate fuel, timig and boost, and also transmitting it to the G5 Tachometer located read more in the instrument cluster. You can determine if the sensor is in failure by examining read more the continuity of 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 and pin T26a/12. It should show around 1000 ohms of resistance between those two pins. This is a typical component across the click here Audi 80, 100 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU, so the best ones could be available in wrecking yards.