How to Replace an audi tt key replacement G28 Engine Speed Sensor
Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. This sensor Replace audi key is located near the edges of the transmission, above the flywheel ring gear. It sends a message to the ECU through the grey wire T55/49 and then to the tachometer on the instrument cluster.
1. Engine Speed Sensor
It is located on the outside of the transmission, above the flywheel ring gear, the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 through an uncolored wire. The ECU uses this information to regulate boost and fuel. It also sends an indication 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 is TDC and where the camshaft is located so that it can trigger spark and injectors according to the situation.
If this sensor fails, the ECU will display a P00160 error message. This indicates that the Crank Shaft is not in line with the Intake Camshaft. It could also be a sign of an issue with the chain or a jumpy chain link in the upper chain. However the code will not appear on its own, without additional information from other sensors (G4 and G40).
It is a little tricky to test since there are various connector pins, 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 if the sensor is at full operation. Examine for evidence of coolant or oil in the connector bay if you have issues with this part.
2. Injectors
Yesterday, while accelerating at full speed from the highway paytoll i had a big cut in power as if the engine was running out of gas or the injectors aren’t firing at all. In the morning, i removed the spark plugs, three were drenched with gazoline the fourth one was dry. When i crank the engine without sparks i put tissue on top of each injector hole and the 3 that were drenched in gazoline pop out, but the 4th stay closed. I checked the ground connection on ECU pins 14/55,30/55 and 48/55 I get zero ohm. I’m assuming that the issue is elsewhere.
I also tried to reset the PID without success. The car will start if the G28 is unplugged and runs fine when it is plugged in but it still has the intermittent misfire issue at higher RPM. The coolant sensor (G62), even when unplugged, still shows a temperature of -49c. Also i noticed that the oil pressure gauge in the cockpit is showing 2 bar when the actual pressure is 0.0 if i crank up the engine.
I don’t know what to do. I think I’ve eliminated everything else. But i am afraid I might have missed something. If anyone has suggestions, please chime in! TIA!
3. Fuel Pump
The fuel pump in the g28 gets a signal from the RPM sensor. The GM-style sensor 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 salvage yard or from a parts store. It is simple to test them – just put your DMM into resistance mode and measure the distance between pins 1 and keys 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) engines needs to know the speed and position of the crankshaft to determine timing of the fuel injector, etc. In order to do this it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these goes wrong, you will receive codes on the diagnostic scanner that can cause the engine to shut down.
A malfunctioning G28 sensor could result in an inaccurate speed counter for the gearbox and a gearbox which shifts more quickly than normal, and/or a misfire while in gear. It is likely that the sensor is failing and requires to be replaced if you notice any of these symptoms. The good thing is that they are quite affordable and easy to find particularly if you’re looking at an Bosch sensor, which is what ours are. Alternately, the GM version of this part is also a great option.
5. Tachometer
A malfunctioning engine sensor can cause a number of problems in your car. It’s a vital component of the replacement audi a3 Key‘s transmission since it relays information to the ECU about how fast or slow the car’s crankshaft is turning. This sensor can cause the transmission to fail and other car components to be affected.
The G5 engine sensor is located at the outskirts of transmission, above the flywheel ring. It sends signals via gray wire to ECU pin T55/49. The ECU then uses and processes this signal to control the flow of fuel, timig and boost, and also transmitting it to the G5 Tachometer located in the instrument cluster. You can determine if the sensor is in failure by examining the 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 [79trace [79]), and between pin T6a/1 as well as pin T26a/12. You should see a resistance of approximately 1000 ohms in these areas. This part is common across the audi a4 key replacement 80-100-200-RS2 series, starting from the 1985 MC all the way up to the 1997 UrS AN and 1995 RS2 DU So, you may find some good ones in wrecking yards.