How to Replace an replacement audi a4 key G28 Engine Speed Sensor

Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. This sensor is situated near the transmission's edge just above the flywheel gear. It sends a message to the ECU via the grey wire T55/49 and then to the tachometer in the instrument cluster.

1. Engine Speed Sensor

The grey wire is located at the edges of the transmission, directly above the flywheel ring. The sensor sends an electrical signal through the grey wire to pin T55/49. The ECU then utilizes this information to regulate the flow of fuel, timig and boost. It also sends an indicator to the G5 Tachometer within the instrument cluster.

The sensor is used as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft reached TDC, and where the camshaft lies so that it can activate the spark and injectors.

If this sensor fails, the ECU will show a P00160 code which means the Crank Shaft and Intake Camshaft are out of sync and possibly indicating chain stretch or a jumped link on the upper timing chain. However the code will not appear on its own without additional information from other sensors (G4 and G40).

It can be a bit difficult to test because there are different 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 about 1000 ohms when it is at full operation. Check for evidence of coolant or oil in the connector bay if you have issues with this component.

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 any more. This morning i pull out the spark plugs. Three were soaked with gazoline and the 4th one was dry. When I start the engine, there are no sparks, I put a piece of tissue on the top of each of the injector holes and the 3 drenched with gazoline leap out, however the 4th stay closed. I inspected the ground connection on ECU pins 14/55, 30/55 and 48/55. i get zero Ohm. I'm assuming the issue is somewhere else.

I also tried to reset the PID but with no luck. The car key cover audi is able to start if the G28 is not plugged in and is running fine when it is connected but it still has the intermittent misfire issue at higher RPM. The coolant sensor (G62), even if it is not plugged in, shows an ice temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bars when the actual pressure is 0.

I'm not sure what to do. I think I've all other possibilities out. I'm concerned that i may have missed something. Let me know If you have any suggestions! TIA!

3. Fuel Pump

The fuel pump in the g28 is activated by a signal sent 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 an extra in a wrecking shop or a parts store. It is easy to test them - just put your DMM into resistance mode and test 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 of our 20vt turbo (3B AAN ABY) engines must know both the position and speed of the crankshaft to make decisions regarding fuel injector timing, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you encounter a problem with either one of these, the diagnostic scanner will display codes that could cause the engine shutting down.

A failing G28 sensor could result in an inaccurate speed counter for your gearbox, a gearbox that shifts more quickly than normal, or an unfire when in the gear. It is likely that your sensor is failing and needs to be replaced if you encounter any of these signs. The good thing is that they are very affordable and easy to find, especially in the case of the Bosch unit which is what we have. Alternatively, GM's version of this part is an option.

5. Tachometer

A failing engine sensor could cause a number of problems in your car. It's a vital component of your audi a5 key fob's transmission, since it relays information to the ECU about how the car's crankshaft is spinning. This sensor audi replacement key service could cause the transmission to malfunction and other components of the car to be affected.

The G5 engine speed sensor is located at the edge of the transmission above the flywheel ring gear. It sends a signal directly to the ECU at pin T55/49 via an uncolored wire. The ECU is then able to process the signal to control fuel, timig and boost, and also sends it on to the G5 tachometer in the instrument cluster. You can determine if the sensor is in failure by checking continuity from the sensor to the tachometer. You can also check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]), and between pin T6a/1 and pin T26a/12. You should see an average resistance of 1000 ohms between these two points. This is a common feature across the Audi A3 Key Fob Replacement 80-100-200-RS2 series, starting from the 1985 MC up to the 1997 UrS AN and the 1995 RS2 Du So, you may find them in wrecking yards.