The 3 Biggest Disasters In Audi G28 History

How to Replace an audi q7 key G28 Engine Speed Sensor

In this video Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is located on the edge of the transmission just above the flywheel ring gear. It sends a signal to the ECU via an uncolored wire (T55/49) and then to the tachometer in the instrument cluster.

1. Engine Speed Sensor

The grey wire is situated at the edges of the transmission, just above the flywheel ring. The sensor sends an electrical signal through the grey wire to pin T55/49. The ECU utilizes this information to control boost and fuel. It also sends an indication to the G5 Tachometer within the instrument cluster.

The sensor is used to link with the G40 Camshaft position Sensor. The ecu must be aware when the crankshaft is TDC and the location of the camshaft so it can activate spark and injectors according to the situation.

If this sensor fails, the ECU will display an error code P00160. This indicates that the Crank Shaft is out of sync with the Intake Camshaft. It could also be a sign of a chain stretch or a jumpy chain link in the upper chain. However, the code won't be displayed on its own without additional information from other sensors (G4 and G40).

Testing is a bit tricky since there are two connector pins, and they have different functions but the most effective method to test it is to measure resistance between the sensor and the ECU. If the sensor is operational, it should be reading around 1000 ohms. If you are having problems with this part, check for evidence of oil or coolant in the connector bay.

2. Injectors

Yesterday, while accelerating at full speed from the highway paytoll i had an abrupt drop in power like the engine is out of gas or the injectors aren't firing any more. I pulled out the spark plugs this morning, 3 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 three with gazoline jump right out. The 4th one stays closed. I checked the ground connection on ECU pins 14/55,30/55 and 48/55 I got zero ohm. I'm assuming that the issue is elsewhere.

I also tried to reset the PID but with no luck. The car will start when the G28 is unplugged, and it works fine when the G28 connected. However the intermittent misfire issue continues to occur at higher RPM. The coolant sensor (G62) even when it is unplugged, shows an ice temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bars but the actual pressure is 0.

I'm not certain what to do, as i think i've pretty much eliminated everything else. I'm concerned that i may have missed something. If anyone has any ideas please chime in! TIA!

3. Fuel Pump

The fuel pump in the g28 can be activated by a signal sent by 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 which is why you can easily locate one at a junkyard or at a parts store. Test them out by putting your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector's end up) and 2 (2nd from the left on the black end of the connector). They should be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY, and ADU) engines have an ECU that must be aware of the speed and position of the crankshaft to make a decision about timing of the fuel injectors, etc. To accomplish this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these sensors go bad you will get codes on the diagnostic scanner that can cause the engine to shut down.

A malfunctioning G28 sensor can cause an inaccurate gearbox speed counter, a gearbox that shifts faster than normal, and/or an unfire when in the gear. It is possible that the sensor is failing and needs to be replaced if you encounter any of these signs. The good news is that they are quite affordable and readily available, especially if you're looking at the 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 failing engine sensor could cause a myriad of issues in your vehicle. It is a crucial part of your audi key fob not working Replacement key for audi service - Https://atavi.com/ -'s transmission, as it sends information to the ECU about how fast or slow the vehicle's crankshaft is rotating. This sensor can cause the transmission to fail and other audi car key cover 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 a gray wire to the ECU pin T55/49. The ECU then uses and processes this signal to regulate the flow of fuel, timig and boost, and also transmitting it to the G5 tachometer in the instrument cluster. You can check the sensor for failure by checking continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should detect a resistance of approximately 1000 ohms between these points. This is a common feature across the audi key copy 80-100-200-RS2 series, starting from the 1985 MC up to the 1997 UrS An and 1995 RS2 DU You may also find them in wrecking yards.