10 Tips For Getting The Most Value From Audi G28

How to Replace an Audi Replacement Key Fob G28 Engine Speed Sensor

Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. The sensor is located at the edge of transmission over the flywheel gear. It sends a message to the ECU through the grey wire T55/49 and then to the tachometer located on the instrument cluster.

1. Engine Speed Sensor

It is located on the outside of the transmission above the flywheel ring gear, the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 through an uncolored wire. The ECU then uses this information to control the flow of fuel, timig and boost. It also sends signals to the G5 Tachometer located in the instrument cluster.

The sensor is used to link the G40 Camshaft position Sensor. The ecu must know when the crankshaft has reached TDC, and the position of the camshaft, to trigger 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 the chain is stretched or a jump link on the upper chain of timing. However the code will not be displayed on its own without additional information from other sensors (G4 and G40).

Testing is a bit tricky because there are two connector pins, and they serve different purposes but the best method to test it is by measuring resistance between the sensor and the ECU. It should read approximately 1000 ohms if the sensor is operating at its maximum. Check for signs of coolant, or oil in the connector bay if you are experiencing problems with this part.

2. Injectors

Yesterday, while accelerating from the highway paytoll at maximum speed I noticed a significant decrease in power. It was as if the engine was running out of gas. Or, my injectors weren't firing. I took out the spark plugs this morning, 3 were soaked with gasoline and the fourth was dry. I put a piece of tissue over each injector hole and when I start the engine without sparks, the three with gazoline jump right out. The fourth one remains closed. I tried to test the ground connections of ECU pins 14,30, and 48/55. I found 0ohm. I think the issue is elsewhere.

I also tried to reset PID but without success. The car will start when the G28 is disconnected, but it runs fine with the G28 connected. However the intermittent misfire issue still occurs at higher RPM. The coolant sensor (G62) even if it is not plugged in, shows temperatures of -49c. Also, i noticed that the oil pressure gauge in the cockpit is showing 2 bar when the actual pressure is 0.0 when i rev the engine.

I'm not certain what to do, i believe that i've eliminated everything else. But i'm worried that I might have missed something. If anyone has suggestions, please chime in! TIA!

3. Fuel Pump

The fuel pump in the g28 receives signals from the RPM sensor. The GM-style sender is the same as the G4 and both are used in the 80, 100 200, UrS and RS2 cars so you can easily find one at a salvage yard or from a parts store. It is simple to test them - just switch your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump on the connector's edge facing upwards). They must be infinite ohms.

4. ECU

The ECU of our 20vt turbo (3B AAN ABY ADU) engines must be aware of the position and speed of the crankshaft to determine timing of the fuel injector, etc. To do this, it makes use of a Crank Position Sensor (G4) and audi key fobs Car Key Replacement Cost (please click the next website) an Engine Speed Sensor (G28). If either of these sensors go wrong, you will receive codes on the diagnostic scanner which can cause the engine to shut down.

Some of the symptoms of a malfunctioning G28 sensor are an inaccurate rev counter for the gearbox, gears shifting quicker than normal and/or misfiring when you are in gear. If you have any of these issues it is likely that your sensor is deteriorating and needs replacing. They're inexpensive and easy to locate particularly when they're a Bosch unit like ours. Alternately, the GM version of this part is also a great option.

5. Tachometer

A damaged engine sensor could cause a number of problems in your car. It's an essential component of the replacement audi key fob's transmission as it sends information to the ECU about how fast or slow the vehicle's crankshaft is spinning. This sensor can cause the transmission to fail and other components in the car to be affected.

The G5 engine speed sensor is located on the outside of the transmission just above the flywheel ring gear. It sends a signal to the ECU at pin T55/49 via an uncolored wire. The ECU then uses and processes this signal to control the flow of fuel, timig and boost as well as transmitting it to the G5 Tachometer located in the instrument cluster. You can test the sensor for failure by examining the continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. It should show approximately 1000 ohms of resistance between those points. This is a common feature across the audi keyfob 80-100-200-RS2 range, from the 1985 MC all the way up to the 1997 UrS AN and the 1995 RS2 Du, so you might find some good ones in wrecking yards.