How to Replace an audi q5 key G28 Engine Speed Sensor

In this video Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is situated on the outside of the transmission, above the flywheel gear. It transmits a signal the ECU via an uncolored wire (T55/49) which is then sent to the tachometer within the instrument cluster.

1. Engine Speed Sensor

The grey wire is located at the edges of the transmission, just above the flywheel ring. The sensor transmits an electrical signal through the grey wire to pin T55/49. The ECU then utilizes this information to regulate the boost, fuel, and timig. It also sends an indication 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 must be aware of when the crankshaft has reached TDC and also where the camshaft lies to trigger the spark and injectors.

If this sensor fails the ECU will display a P00160 code which means the Crank Shaft and Intake Camshaft are out of sync, possibly indicating chain stretch or a jumped link on the upper timing chain. The code won't show without the additional information supplied by other sensors (G4 or G40).

Testing can be a bit difficult because there are two pins for the connector and they perform different functions but the best 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. Examine for signs of coolant or oil in the connector bay if there are problems with this part.

2. Injectors

Yesterday, as i was accelerating off the highway paytoll at a high speed, i noticed a huge decrease in power. It was as if the engine was running out of gas. Or, my injectors were not firing. I pulled out the spark plugs this morning, three were drenched in gasoline and the fourth was unclean. When i crank the engine without sparks, I put a piece of tissue on top of each injector hole and the 3 drenched with gazoline jump out but the 4th stay closed. I inspected the ground connection on ECU pins 14/55,30/55 and 48/55 i get zero ohm. So i assume the problem is elsewhere.

I also tried to reset the PID with no success. The car is able to start if the G28 is disconnected and it runs perfectly when it is connected but it still is experiencing intermittent misfires at higher RPM. The coolant sensor (G62), even if it is not plugged in, shows a temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bar when the actual pressure is zero.

I'm not certain what to do, as i think i've pretty much completely ruled out all other possibilities. I'm afraid i may have missed something. If anyone has any suggestions, please let me know! TIA!

3. Fuel Pump

The fuel pump in the g28 can be activated by a signal by the RPM sensor. The GM-style transmitter is identical to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. You can easily locate a spare in a wrecking shop or parts store. It is easy to test them: simply put your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector end facing up). They should 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 make decisions regarding fuel injector timing, etc. To do this, it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you are experiencing issues with either of these sensors, the diagnostic scanner will show codes that could lead to the engine shutting down.

A damaged G28 sensor could result in an inaccurate gearbox speed counter and a gearbox which shifts more quickly than normal, and/or a misfire in gear. If you experience any of these issues, it is likely your sensor is going bad and should be replaced. The good news is that they are very cheap and easily accessible particularly when you're looking at an Bosch unit which is what ours are. You can also choose the GM version of this part is also a great option.

5. Tachometer

A faulty engine speed sensor could be the reason behind a slew of issues in your car. It's a crucial component of the transmission in your replacement audi key audi car keys key for audi fob (visit the following website), as it transmits information to the ECU about how fast or slow the engine 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 edge of the transmission, over the flywheel ring. It transmits a signal via an uncolored wire to the ECU pin T55/49. The ECU utilizes this signal to regulate the flow of fuel and boost and also to timigrate. It also transmits it to the G5 Tachometer located in the instrument cluster. You can check 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]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should see around 1000 ohms of resistance between those points. This part is common across the replacement audi a4 key 80-100-200-RS2 model, ranging from the 1985 MC up to the 1997 UrS AN and the 1995 RS2 DU You may also find them in wrecking yards.