How to Replace an
Audi Key Replacement Cost G28 Engine Speed Sensor
In this video, Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is located at the top of the transmission just above the flywheel ring gear. It sends a message to the ECU via an uncolored wire T55/49, 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 the grey wire. The ECU then uses this information to control fuel, timig and boost. It also sends an indication to the G5 tachometer inside the instrument cluster.
The sensor serves as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must be aware 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 an error code P00160. This means that the Crank Shaft is not in sync with the Intake Camshaft. It could also be a sign of a chain stretch or a jumpy chain link in the upper timing chain. The code won't appear without the additional information provided by other sensors (G4 or G40).
Testing is a bit tricky because there are two pins for the connector and they have different functions but the most effective way to test it is to measure resistance between the sensor and the ECU. It should read approximately 1000 ohms when the sensor is at full operation. Check 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 experienced massive power loss as if the engine was running out of gas or the injectors aren't firing any more. I pulled out the spark plugs this morning, three were drenched in gasoline and the 4th was dry. I put tissue over each hole in the injector and when i start the engine without sparks, the ones with gazoline jump out. The 4th one stays shut. I inspected the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ i get 0ohm. 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 is running fine with the G28 connected. However, the intermittent misfire problem continues to occur 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 gauge for oil pressure in the cockpit is showing 2 bar, whereas the actual pressure is 0.0 when i rev the engine.
I'm not certain what to do, i believe that i've ruled out everything else. However, i'm afraid that I may have missed something. If anyone has any ideas please let me know! TIA!
3. Fuel Pump
The fuel pump in the g28 receives a signal from the RPM sensor. The GM-style sensor is identical to the G4 and both are used 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 simple to test them by putting your DMM in resistance mode and measure between pins 1 (with the bump on the connector's side up) and 2 (2nd from the left on the black end of the connector). They must be infinite Ohms.
4. ECU
Our 20vt turbo (3B,
audi key replacement Cost AAN, ABY and ADU) engines have an ECU that has to know the speed and position of the crankshaft in order to make a decision about fuel injector timing etc. To do this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you encounter a problem with either of these sensors, the diagnostic scanner will display the codes that could trigger the engine shutting down.
A damaged G28 sensor could cause an inaccurate speed counter for the gearbox and a gearbox which shifts faster than normal, and/or a misfire in gear. If you have any of these issues, it is most likely that your sensor is failing and needs replacing. They are cheap and easy-to-find, especially in the case of a Bosch model like ours. Alternately, the GM version of this component is also a good option.
5. Tachometer
A damaged engine sensor could cause a variety of issues within your vehicle. It is a crucial part of your
audi keys replacement's transmission, since it relays information to the ECU about how fast or slow the car's crankshaft is spinning. If this sensor fails, it will disrupt the performance of the transmission and the rest of the car's components.
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 utilizes this signal to control the amount of fuel and boost, as well as timig. It also relays it to the G5 Tachometer inside the instrument cluster. You can test the sensor for failure by examining the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should detect the resistance to be around 1000 ohms between these two points. This part is common across the
replacement key audi 80-100-200-RS2 model, ranging beginning with the 1985 MC and up to the 1997 UrS AN and the 1995 RS2 Du You may also find them in wrecking yards.