10 Things You ve Learned In Preschool That ll Help You Understand Audi G28

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. The sensor is situated near the edges of the transmission, above the flywheel ring gear. It sends a signal to the ECU via a grey wire (T55/49), then to the tachometer in the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated on the outside of the transmission, directly above the flywheel ring. The sensor transmits a signal via 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 a signal to the G5 tachometer inside the instrument cluster.

The sensor is used to link the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft is TDC and the location of the camshaft so it can start spark and injectors in the right way.

If this sensor fails, the ECU will show an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are out of sync and could indicate the chain is stretched or a jump link on the upper timing chain. The code won't show without the additional information supplied by other sensors (G4 or G40).

It is a little tricky to test as there are different connector pins, and they all have different functions. The best way to do it is by measuring the resistance between the ECU and the sensor. When the sensor is fully functional, it should read approximately 1000 ohms. Look for signs of coolant, or oil in the connector bay if you have issues with this part.

2. Injectors

Yesterday, as i was accelerating off the highway paytoll at full speed I noticed a significant drop in power. It was as if the engine had run out of gas. Or my injectors were not firing. In the morning, i removed the spark plugs, 3 were drenched with gazoline the fourth one was dry. I placed a tissue over each injector hole, and when i start the engine with no sparks, the 3 that have gazoline pop right out. The 4th one remains shut. I tested the ground connection on ECU pins 14/55, 30/55 and 48/55. i get zero Ohm. I assume that the problem is elsewhere.

I also tried to reset the PID but without success. The car will start when the G28 is unplugged, and it is running fine with the G28 connected. However the intermittent misfire issue still occurs at higher RPM. The coolant sensor (G62) even when unplugged, still shows an ice temperature of -49c. Also i noticed that the oil pressure gauge in the cockpit shows 2 bar, whereas the actual pressure is 0.0 when i rev the engine.

I'm not certain what to do, but i believe that i've ruled out everything else. But i am afraid I might have missed something. Please let me know If you have any suggestions! TIA!

3. Fuel Pump

The fuel pump of the g28 receives a signal from the RPM sensor. The GM-style sensor is identical to the G4 and they both work in the 80, 100 200, UrS and RS2 cars so you can easily find one at a wrecking yard or from a parts store. Testing them is easy - put your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector end up) and 2 (2nd from left on the black end of the connector). They should be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY ADU) engines must know both the position and speed the crankshaft to make decisions regarding fuel injector timing, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you are experiencing issues with either one of these, the diagnostic scanner will display the codes that could trigger an engine shut down.

The signs of a failed G28 sensor include an inaccurate rev counter for the gearbox, gears shifting quicker than normal and/or misfiring when in gear. If you experience any of these issues, it is likely that your sensor is failing and should be replaced. The good news is that they are quite affordable and easily accessible particularly in the case of a Bosch sensor, like ours. Alternately, GM's version this part would be a good option.

5. Tachometer

A failing engine sensor could cause a number of problems in your vehicle. It's a crucial component of the transmission in your audi car key cover smart key audi replacement key (click to find out more) because it relays information to the ECU regarding how fast or slow the engine is spinning. If this sensor fails, it could disrupt the performance of the transmission and the rest of the car's components.

The G5 engine speed sensor is located on the edge of the transmission, above the flywheel ring gear. It sends a signal to the ECU at pin T55/49 via an uncolored wire. The ECU utilizes this signal to control the amount of fuel and boost, and also timig. It also sends it to the G5 Tachometer located in the instrument cluster. You can check for sensor failure by examining the continuity of the sensor to the tachometer. Additionally, you can 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 and pin T26a/12. You should see the resistance to be around 1000 ohms in these areas. This part is common across the programming audi key 80-100-200-RS2 series, starting from the 1985 MC up to the 1997 UrS An and 1995 RS2 Du, so you might find them in wrecking yards.