10 Times You'll Have To Be Educated About Audi G28
How to Replace an Audi A1 Key fob G28 Engine Speed Sensor
Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. This sensor is located on the edge of the transmission, above the flywheel ring gear. It sends a message to the ECU via 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 an electrical signal to ECU pin T55/49 through the grey wire. The ECU uses this information to control boost and fuel. It also sends an alert to the G5 Tachometer located 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 reached TDC and also the position of the camshaft, to trigger the spark and injectors.
If this sensor fails when it fails, the ECU will display an error code P00160. This indicates that the Crank Shaft is out of line with the Intake Camshaft. It could also indicate an issue with the chain or a jumpy chain link in the upper timing chain. 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 one has different functions. The most effective method to test it is by measuring the resistance between the ECU and the sensor. When the sensor is fully functional, it should read about 1000 ohms. Check for evidence of coolant or oil in the connector bay if you have issues with this part.
2. Injectors
Yesterday, when i was accelerating to the fullest speed from highway paytoll, i experienced a big cut in power like the engine is out of gas or the injectors aren't firing at all. I took out the spark plugs this morning, three were soaked in gasoline, and the fourth was unclean. When i crank the engine without sparks i put tissue on the top of each hole in the injector and the 3 drenched with gazoline leap out, however the 4th stay closed. I tested the ground connection on ECU pins 14/55, 30/55 and 48/55. I get zero ohm. I'm assuming the issue is in another place.
I also tried to reset the PID but with no luck. The car will start when the G28 is unplugged and it runs perfectly when it is connected but it still is experiencing intermittent misfires at higher RPM. The coolant temperature sensor (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 think I've all other possibilities out. I'm worried that i might have missed something. If anyone has suggestions, please share them! TIA!
3. Fuel Pump
The fuel pump of the g28 receives signals from the RPM sensor. The GM-style sender is the same as the G4 and they both work in the 80 100, 200, UrS and RS2 cars so you can easily find one at a salvage yard or from a parts store. It is easy to test them - simply put your DMM into resistance mode and determine 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 in our 20vt turbo (3B AAN ABY ADU) engines must be aware of the position and speed the crankshaft to determine timing of the fuel injector, etc. In order to do this it makes use of a Crank Position Sensor (G4) and replacement Key for audi a3 an Engine Speed Sensor (G28). If you are experiencing issues with either of these, the diagnostic scanner will show codes that could cause an engine shutdown.
A failing G28 sensor can cause an inaccurate speed counter for the gearbox, a gearbox that shifts faster than normal, and/or an unfire when in gear. It is probable that the sensor is failing and requires to be replaced if you notice any of these symptoms. They're cheap and easy to find, especially if they're a Bosch unit like ours. Alternatively, 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 vehicle. It's an essential component of your audi a3 keys's transmission, because it communicates to the ECU about how fast or slow the vehicle's crankshaft is rotating. This sensor could cause the transmission to fail and other components in the car to be affected.
The G5 engine speed sensor is located on the edge of the transmission, above the flywheel ring gear and sends a signal to the ECU at pin T55/49 through a grey wire. The ECU utilizes this signal to control fuel and boost, and also timig. It also sends it to the G5 Tachometer inside the instrument cluster. You can check the sensor for failure by checking continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. There should be an average resistance of 1000 ohms in these areas. This is a common part that is found across the audi a3 spare key 80 100, 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU. Good ones could be available in wrecking yards.
Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. This sensor is located on the edge of the transmission, above the flywheel ring gear. It sends a message to the ECU via the grey wire T55/49 and then to the tachometer on the instrument cluster.
1. Engine Speed SensorIt is located on the outside of the transmission, above the flywheel ring gear, the G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 through the grey wire. The ECU uses this information to control boost and fuel. It also sends an alert to the G5 Tachometer located 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 reached TDC and also the position of the camshaft, to trigger the spark and injectors.
If this sensor fails when it fails, the ECU will display an error code P00160. This indicates that the Crank Shaft is out of line with the Intake Camshaft. It could also indicate an issue with the chain or a jumpy chain link in the upper timing chain. 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 one has different functions. The most effective method to test it is by measuring the resistance between the ECU and the sensor. When the sensor is fully functional, it should read about 1000 ohms. Check for evidence of coolant or oil in the connector bay if you have issues with this part.
2. Injectors
Yesterday, when i was accelerating to the fullest speed from highway paytoll, i experienced a big cut in power like the engine is out of gas or the injectors aren't firing at all. I took out the spark plugs this morning, three were soaked in gasoline, and the fourth was unclean. When i crank the engine without sparks i put tissue on the top of each hole in the injector and the 3 drenched with gazoline leap out, however the 4th stay closed. I tested the ground connection on ECU pins 14/55, 30/55 and 48/55. I get zero ohm. I'm assuming the issue is in another place.
I also tried to reset the PID but with no luck. The car will start when the G28 is unplugged and it runs perfectly when it is connected but it still is experiencing intermittent misfires at higher RPM. The coolant temperature sensor (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 think I've all other possibilities out. I'm worried that i might have missed something. If anyone has suggestions, please share them! TIA!
3. Fuel Pump
The fuel pump of the g28 receives signals from the RPM sensor. The GM-style sender is the same as the G4 and they both work in the 80 100, 200, UrS and RS2 cars so you can easily find one at a salvage yard or from a parts store. It is easy to test them - simply put your DMM into resistance mode and determine 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 in our 20vt turbo (3B AAN ABY ADU) engines must be aware of the position and speed the crankshaft to determine timing of the fuel injector, etc. In order to do this it makes use of a Crank Position Sensor (G4) and replacement Key for audi a3 an Engine Speed Sensor (G28). If you are experiencing issues with either of these, the diagnostic scanner will show codes that could cause an engine shutdown.
A failing G28 sensor can cause an inaccurate speed counter for the gearbox, a gearbox that shifts faster than normal, and/or an unfire when in gear. It is probable that the sensor is failing and requires to be replaced if you notice any of these symptoms. They're cheap and easy to find, especially if they're a Bosch unit like ours. Alternatively, 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 vehicle. It's an essential component of your audi a3 keys's transmission, because it communicates to the ECU about how fast or slow the vehicle's crankshaft is rotating. This sensor could cause the transmission to fail and other components in the car to be affected.
The G5 engine speed sensor is located on the edge of the transmission, above the flywheel ring gear and sends a signal to the ECU at pin T55/49 through a grey wire. The ECU utilizes this signal to control fuel and boost, and also timig. It also sends it to the G5 Tachometer inside the instrument cluster. You can check the sensor for failure by checking continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. There should be an average resistance of 1000 ohms in these areas. This is a common part that is found across the audi a3 spare key 80 100, 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU. Good ones could be available in wrecking yards.