The 3 Biggest Disasters In Audi G28 History

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

In this video Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. This sensor is located at the top of the transmission above the flywheel ring 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 sensor is located at the edge of the transmission just above the flywheel ring gear the G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 through the grey wire. The ECU then uses this information to control the flow of fuel, timig and boost. It also sends a signal to the G5 tachometer in the instrument cluster.

The sensor is used to connect 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 activate spark and injectors according to the situation.

If this sensor fails the ECU will display an error code P00160 which indicates that the Crank Shaft and Intake Camshaft aren't in sync and could indicate chain stretch or a jumped link on the upper chain of timing. The code won't appear without the additional information supplied by other sensors (G4 or G40).

Testing can be a bit difficult because there are two connector pins, and they perform different functions however the best way to test it is to measure the resistance between the sensor and the ECU. It should read approximately 1000 ohms when it is operating at its maximum. If you're experiencing issues with this sensor, audi car key replacement look for signs 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 as if the engine was running out of gas or the injectors are not firing any more. Today, i pulled out the spark plugs. Three were drenched in gazoline, the fourth one was dry. When i crank the engine with 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 14/55/30/55/48/55/14/55/48/ i get zero Ohm. I assume that the problem is somewhere else.

I also tried to reset PID without success. The car can start if the G28 is not plugged in and is running fine when it is connected however it has the intermittent misfire issue 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 bar when the actual pressure is 0.

I'm not sure what to do, but i believe that i've ruled out everything else. 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 receives signals 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 at a parts store. Test them out to do - just put your DMM in resistance mode and measure between pins 1 (with the bump on the connector end up) and 2 (2nd from left on the black end of the connector). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY and ADU) engines are equipped with an ECU that must know the position and speed of the crankshaft to make decisions about timing of the fuel injectors, etc. To accomplish this, it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you are experiencing issues with either one of these, the diagnostic scanner will show codes that could lead to an engine shut down.

Some of the symptoms of a failed G28 sensor are an inaccurate rev counter for the gearbox, gears shifting quicker than normal and/or a misfire when in gear. It is likely that your sensor is failing and requires to be replaced if you notice any of these signs. The good news is that they are very cheap and easily accessible, especially when you're looking at a Bosch unit which is what ours are. If you prefer, GM's version of this part would be an excellent choice.

5. Tachometer

A failing engine sensor could cause a number of problems within your vehicle. It's a crucial component of the transmission of your audi a4 replacement key because it relays information to the ECU about how fast or slowly the engine is spinning. If the sensor fails, it could affect the performance of the transmission, as well as the rest of the car's components.

The G5 engine sensor is located at the edge of transmission, above the flywheel ring. It sends signals via gray wire to ECU pin T55/49. The ECU utilizes this signal to control fuel and boost, and also timig. It also relays 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. You can also check continuity between ECU pin T55/49 and the instrument cluster connection via pin T6a/1 (trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. It should show approximately 1000 ohms resistance between those points. This is a typical part across the audi car key replacement Cost 80, 100, 200, UrS and RS2 range from 1985 MC until the 1997 UrS AAN and 1995 RS2 ADU so good parts could be found in wrecking yards.