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 on the outside of the transmission over the flywheel gear. It transmits a signal to the ECU via the grey 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 utilizes this information to regulate boost and fuel. audi a4 spare key sends an alert to the G5 Tachometer within the instrument cluster.
The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft is TDC and the location of the camshaft so it can start spark and injectors according to the situation.
If this sensor fails to function, the ECU will display an error code P00160. This indicates that the Crank Shaft is not in alignment with the Intake Camshaft. It could also indicate the possibility of a chain stretch or jumpy chain link in the upper timing chain. However, the error code won't appear on its own without additional information from other sensors (G4 and G40).
It's a bit tricky to test as there are several pins on the connector and each one has different functions. The most effective method to test it is to measure the resistance between the ECU and the sensor. It should read approximately 1000 ohms when it is at full operation. Examine for evidence of coolant or oil in the connector bay if you are experiencing problems with this part.
2. Injectors
Yesterday accelerating full speed from highway paytoll i had a big cut in power like the engine is running out of gas or the injectors are not firing at all. In the morning, i removed the spark plugs, 3 were soaked with gazoline and the fourth was dry. When I start the engine with no sparks, I put a piece of tissue on top of each injector hole and the 3 drenched with gazoline jump out but the 4th one stays closed. I inspected the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I got 0ohm. I'm assuming that the issue is in another location.
I also tried to reset the PID but without success. The car will start if the G28 is unplugged and is running fine when it is plugged in but it still is experiencing intermittent misfires at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature of that is -49c even after unplugging it. Also i noticed that the oil pressure gauge in the cockpit is showing 2 bar while the actual pressure is 0.0 if i crank up the engine.
I don't know what to do. I believe that I've all other possibilities out. But i'm worried that I may have missed something. Please let me know if you have any ideas! TIA!
3. Fuel Pump
The fuel pump of the g28 receives a signal from the RPM sensor. The GM-style transmitter is identical to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. You can easily find a spare in a wrecking shop or parts store. Test them out by putting your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector end up) and 2 (2nd from the left on the black end of the connector). They must be infinite Ohms.
4. audi a3 key replacement near me of our 20vt turbo (3B AAN ABY) engines must know both the speed and position of the crankshaft in order to make a decision about timing of fuel injectors, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you are experiencing issues with either of these sensors, the diagnostic scanner will display codes that could cause the engine shutting down.
A malfunctioning G28 sensor could cause an inaccurate speed counter for your gearbox and a gearbox which shifts faster than normal, or an unfire when in gear. It is likely that your sensor is failing and requires to be replaced if you notice any of these symptoms. They're inexpensive and easy to locate especially if they're an Bosch sensor like ours. Alternately, GM's version this part is an option.
5. Tachometer
A damaged engine sensor could cause a variety of issues within your vehicle. It is a crucial part of your Audi's transmission, since it relays information to the ECU about how the car's crankshaft is turning. This sensor can cause the transmission to malfunction and other car components to be affected.
The G5 engine sensor is located at the outskirts of transmission, above the flywheel ring. It sends an electrical signal through an uncolored wire to the ECU pin T55/49. The ECU is then able to process the signal to control the flow of fuel, timig and boost as well as transmitting it to the G5 tachometer in the instrument cluster. You can check for sensor failure by examining the continuity from the sensor to the tachometer. You can also verify continuity between pin 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. It should show around 1000 ohms of resistance between those points. This is a common feature across the Audi 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.