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 edges of the transmission above the flywheel ring gear. It transmits a signal the ECU via an uncolored wire (T55/49) and then to the tachometer within the instrument cluster.
1. Engine Speed Sensor
It is located on the outside of the transmission just 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 uses this information to control the amount of fuel and boost. It also sends signals to the G5 tachometer in the instrument cluster.
The sensor is used to correlate the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft reached TDC, and the location of the camshaft so that it can activate the spark and injectors.
If this sensor fails when it fails, the ECU will display a P00160 error message. This means that the Crank Shaft is not in sync with the Intake Camshaft. It could also be a sign of the possibility of a chain stretch or jump in the chain link of the upper chain of timing. The code won't appear without the additional information supplied by other sensors (G4 or G40).
Testing is a bit tricky as there are two different connector pins, and they perform different functions however the best method to test it is to measure resistance between the sensor and the ECU. If the sensor is functional, it should read around 1000 ohms. If you're experiencing issues with this component, look for evidence of oil or coolant in the connector bay.
2. Injectors
Yesterday, when accelerating from highway paytoll at a high speed I noticed a massive decrease in power. It was like the engine had run out of gas. Or, my injectors weren't firing. I pulled out the spark plugs this morning, three were soaked with gasoline and the fourth was unclean. I placed a tissue over each injector hole, and when I start the engine with no sparks, the 3 with gazoline jump right out. The 4th one remains shut. I checked the ground connection on ECU pins 14/55, 30/55 and 48/55. I get zero ohm. I think the issue is elsewhere.
I also tried to reset PID without success. The car will start when the G28 is unplugged, and it runs fine with the G28 connected. However, the intermittent misfire problem persists at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature value of -49c even when i unplug it. I also noticed that the gauge for oil pressure 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, but i believe that audi car keys i've completely ruled out all other possibilities. I'm worried that i might have missed something. Please audi a3 key replacement let me know should you have any suggestions! 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 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. It is simple to test them - simply switch your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump at the connector end facing up). They must be infinite Ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY ADU) engines audi a4 spare key must be aware of the speed and position of the crankshaft in order to make a decision about timing of fuel injectors, etc. To accomplish this, it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you are experiencing issues with either of these sensors, the diagnostic scanner will display codes that could cause an engine shutdown.
A damaged G28 sensor could cause an inaccurate speed counter for the gearbox, a gearbox that shifts faster than normal, or an unfire when in gear. It is likely that the sensor is failing and needs to be replaced if you encounter any of these signs. The good news is that they are very cheap and easy to find particularly when you're looking click here at a Bosch sensor, like ours. Alternatively, the GM version of this part is also a good choice.
5. Tachometer
A failing engine sensor could cause a number of problems within your vehicle. It's a crucial component of the transmission of your Audi because it relays information to the ECU about how fast or slowly the car's engine is spinning. When this sensor fails, it can cause problems for the transmission and the other 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 directly to the ECU at pin T55/49, via an uncolored wire. The ECU then processes the signal to control the flow of fuel, timig and boost and then sends it on to the G5 tachometer inside the instrument cluster. You can test the sensor for failure by checking continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should see approximately 1000 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 audi a5 replacement key the 1995 RS2 DU So, you may find good ones in wrecking yards.