7 Little Changes That'll Make A Big Difference In Your Audi G28

How to Replace an audi Keyless go G28 Engine Speed Sensor

In this video Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. The sensor is located near the edges of the transmission just above the flywheel ring gear. It sends a message to the ECU through a grey wire T55/49, 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 signals to ECU pin T55/49 using a grey wire. The ECU utilizes this information to regulate fuel and boost. It also sends an alert to the G5 Tachometer located in the instrument cluster.

The sensor serves as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft is TDC and where the camshaft is located so that it can activate spark and injectors in the right way.

If this sensor fails, the ECU will display a P00160 error message. This means that the Crank Shaft is out of line with the Intake Camshaft. It could also be a sign of a chain stretch or a jumpy chain link in the upper chain of timing. The code won't appear without the additional information supplied by other sensors (G4 or G40).

Testing is a bit tricky since there are two connector pins, and they serve different purposes however the best method to test it is by measuring resistance between the sensor and the ECU. When the sensor is fully operational, it should be reading around 1000 ohms. Check for signs 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 experienced an abrupt drop in power like the engine is out of gas or the injectors aren't firing any more. I took out the spark plugs this morning and found that 3 were drenched in gasoline and the 4th was dry. When I start the engine, there are no sparks, i place a tissue on the top of each hole in the injector, the 3 drenched with gazoline pop out, but the 4th stays shut. I tested the ground connection on ECU pins 14/55,30/55 and 48/55 I get zero ohm. I think the issue is somewhere else.

I also tried to reset the PID without success. The car is able to start when the G28 is disconnected and is running fine when it is connected but it still has intermittent misfire issues at higher RPM. The coolant sensor (G62) even when unplugged, still shows a temperature of -49c. Also i noticed that the oil pressure gauge in the cockpit shows 2 bar when the actual pressure is 0.0 when I crank up the engine.

I'm audi key fob not working certain what to do, i believe that i've completely ruled out all other possibilities. I'm worried that i might 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 from the RPM sensor. The GM-style transmitter is the same as the G4 and they both work in the 80, 100, 200, UrS and RS2 cars so you can easily find one at a salvage yard or at a parts store. Testing them is easy by putting your DMM in resistance mode and measure between pins 1 (with the bump on the connector's end up) and 2 (2nd from the left on the black connector's end). They must be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY ADU) engines needs to be aware of the position and speed the crankshaft to determine fuel injector timing, etc. To do this, it utilizes 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 the codes that could trigger the engine shutting down.

Some of the signs of a failing G28 sensor include an inaccurate rev counter for the gearbox and gears that shift faster than normal, and/or a misfire when you're in gear. If you experience any of these issues it is likely your sensor is going bad and requires replacement audi a3 key. They're inexpensive and easy to locate, especially if they're a Bosch model like ours. If you prefer, GM's version of this component is a good option.

5. Tachometer

A faulty engine speed sensor could be the reason behind many issues with your car. It is an important part of the transmission of your audi q7 key, as it transmits information to the ECU about how fast or slowly the engine is turning. This sensor could cause the transmission to malfunction and other components in the car to be affected.

The G5 engine sensor is located near the edge of the transmission, just above the flywheel ring. It transmits signals via gray wire to ECU pin T55/49. The ECU uses this signal to regulate the flow of fuel and boost and also to timigrate. It also relays it to the G5 Tachometer located in the instrument cluster. You can test for sensor failure by examining the continuity from the sensor to the tachometer. Also, you can verify continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]) and between pin T6a/1 as well as pin T26a/12. It should show approximately 1000 ohms resistance between those two pins. This is a common feature across the spare audi key 80-100-200-RS2 model, ranging beginning with the 1985 MC and up to the 1997 UrS AN and 1995 RS2 DU You may also find some good ones in wrecking yards.