How To Outsmart Your Boss Audi G28
How To Outsmart Your Boss 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 located on the edge of the transmission just above the flywheel ring gear. It transmits a signal to the ECU via an uncolored wire (T55/49), then to the tachometer located in the instrument cluster.
1. Engine Speed Sensor
It is located on the outside of the transmission, above the flywheel ring gear G28 Engine Speed Sensor sends a signal to ECU pin T55/49 through an uncolored wire. The ECU utilizes this information to regulate fuel and boost. It also sends an alert to the G5 Tachometer located in the instrument cluster.
The sensor serves as a reference for comparing with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft reached TDC and also the position of the camshaft, in order to activate the spark and injectors.
If this sensor fails, the ECU will show the P00160 error, which means the Crank Shaft and Intake Camshaft aren't in sync and could indicate the chain is stretched or a jump link on the upper chain of timing. The code will not appear without the additional information provided by other sensors (G4 or G40).
It's a bit tricky to test because there are different pins on the connector, and each has its own functions. The most effective method to test it is by measuring the resistance between the ECU and the sensor. It should read approximately 1000 ohms if the sensor is operating at its maximum. Look for signs of coolant or oil in the connector bay if there are problems with this part.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at full speed I noticed a significant drop in power. It was as if the engine had run out of gas. Or, my injectors were not firing. In the morning, i removed the spark plugs, 3 were soaked with gazoline and the 4th 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 stays closed. I tested the ground connection of ECU pins 14,30 and 48/55. I got 0ohm. I think the issue is elsewhere.
I also tried to reset the PID without success. The car will start when the G28 is unplugged and it more info runs perfectly when it is connected but it still has the intermittent misfire issue at higher RPM. The coolant temperature sensor (G62) shows the wrong temperature value of -49c, even if I unplug it. I also noticed that the gauge for oil pressure in the cockpit shows 2 bar when the actual pressure is check here 0.0 when I crank up the engine.
I'm not sure what to do, i feel i have pretty much ruled out everything else. I'm worried that i might have missed something. Let me know If you have any suggestions! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal sent from read more the RPM sensor. The GM-style sender is identical to the G4 and they both work in the 80 100, 200, UrS and RS2 cars which is why you can easily locate one at a junkyard or in a local parts store. Testing them is easy - put your DMM in resistance mode and measure website between pins 1 (with the bump on the connector's side up) and 2 (2nd from left on the black connector's side). They must be infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B more info AAN ABY ADU) engines requires to be aware of the position and speed the crankshaft to determine timing of fuel injectors, etc. 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 sensors, the diagnostic scanner will display the codes that could trigger the engine shutting down.
The signs of a failed G28 sensor are an inaccurate rev counter in the gearbox and gears that shift faster than normal, and/or a misfire when in gear. It is probable that your sensor is failing and requires to be replaced if you experience any of these signs. They're inexpensive and easy to locate especially if they're an Bosch model like ours. Alternatively, the GM version of this component is also a good option.
5. Tachometer
A faulty engine speed sensor could be the cause of numerous issues with your car. It's a vital component of your Audi's transmission, since it relays information to the ECU about how fast or slow the car's crankshaft is rotating. If this sensor fails, it will affect the performance of the transmission, as well as the rest of the car's components.
The G5 engine sensor is located at the edge of the transmission, just above the flywheel ring. It sends a signal via a gray wire to the ECU pin T55/49. The ECU uses this signal to control the flow of fuel and boost and also timig. It also sends it to the G5 Tachometer located in the instrument cluster. You can check for sensor failure by checking continuity from 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 [79]), and between pin T6a/1 as well as pin T26a/12. You should detect an average resistance of 1000 ohms between these two points. 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 1995 RS2 DU So, you may find good ones in wrecking yards.