How to Replace an replacement audi a3 key G28 Engine Speed Sensor
In this video, Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is located on the outside of the transmission over the flywheel gear. It sends a message to the ECU through a grey wire T55/49, then to the tachometer on the instrument cluster.
1. Engine Speed Sensor
The grey wire is located on the edge of transmission, just above the flywheel ring. The sensor transmits signals through the grey wire to pin T55/49. The ECU uses this information to regulate the amount of fuel and boost. It also sends an indicator to the G5 Tachometer located in the instrument cluster.
The sensor is used to connect with the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft is TDC and the location of the camshaft so it can activate spark and injectors according to the situation.
If this sensor fails, the ECU will display a P00160 error code. This means that the Crank Shaft is not in sync with the Intake Camshaft. It could also indicate a chain stretch or a jumped chain link in the upper chain. However the code will not appear on its own without additional information from other sensors (G4 and Audi Keys G40).
Testing is a bit challenging because there are two pins for the connector and they serve different purposes however the best way to test it is to measure the resistance between the sensor and the ECU. It should read around 1000 ohms when it is at full operation. If you are having problems with this sensor, look for evidence of coolant or oil in the connector bay.
2. Injectors
Yesterday, when accelerating from highway paytoll at full speed, i noticed a huge drop in power. It was as if the engine had run out of gas. Or, my injectors weren't firing. I took out the spark plugs this morning, 3 were soaked with gasoline and the fourth was unclean. When i crank the engine with no sparks, i place a tissue on the top of each hole in the injector, the 3 drenched with gazoline pop out, but the 4th stays closed. I tried to test the ground connections of ECU pins 14,30 and 48/55. I got zero ohm. I'm assuming that the issue is somewhere else.
I also tried to reset the PID but with no luck. The car will start when the G28 is disconnected, but it works fine when the G28 connected. However, the intermittent misfire problem continues to occur at higher RPM. The coolant sensor (G62), even when unplugged, still shows temperatures of -49c. I also noticed that the oil gauge in the cockpit shows 2 bars while the actual pressure is zero.
I'm not sure what to do, as i think i've pretty much completely ruled out all other possibilities. I'm concerned that i may have missed something. Please let me know if you have any ideas! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal by the RPM sensor. The GM-style transmitter functions similarly to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. You can easily locate the spare in a salvage shop or Audi replacement keys 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 on the connector's edge facing upwards). They should be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY, and ADU) engines have an ECU that must know the position and speed of the crankshaft in order to make decisions regarding fuel injector timing etc. To accomplish this, it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you have a problem with either of these, the diagnostic scanner will show codes that could lead to an engine shutdown.
A failing G28 sensor could cause an inaccurate gearbox speed counter, a gearbox that shifts more quickly than normal, and/or a misfire while in the gear. If you experience any of these issues, it is most likely that your sensor audi q3 key is deteriorating and needs replacing. They're cheap and easy to find especially when they're an Bosch model like ours. Alternatively, GM's version of this component is an option.
5. Tachometer
A malfunctioning engine sensor can cause a number of problems in your vehicle. It's a crucial component of the transmission in your audi key Replacement cost uk since it sends information to the ECU about how fast or slowly the engine of the car is spinning. This sensor could cause the transmission to fail and other car components to be affected.
The G5 engine sensor is located at the outskirts of the transmission, just above the flywheel ring. It transmits a signal via gray wire to ECU pin T55/49. The ECU then uses and processes this signal to regulate fuel, timig, and boost as well as transmitting it to the G5 tachometer inside the instrument cluster. You can test the sensor for any failure by checking the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should see an average resistance of 1000 ohms between these two points. This is a common feature across the audi smart key replacement 80-100-200-RS2 range, from the 1985 MC all the way up to the 1997 UrS AN and 1995 RS2 Du, so you might find good ones in wrecking yards.