Audi G28: 10 Things I'd Like To Have Learned Earlier How to Replace an Audi 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, above the flywheel ring gear. It transmits a signal to the ECU via an uncolored wire (T55/49), then to the tachometer within 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 an uncolored wire. The ECU utilizes this information to control the amount of fuel and boost. It also sends an indicator to the G5 Tachometer located in the instrument cluster.


The sensor serves as a reference point to connect with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft reached TDC and also where the camshaft lies so that it can activate the spark and injectors.

If this sensor fails, the ECU will display a P00160 error message. audi car keys means that the Crank Shaft is not in sync with the Intake Camshaft. It could also indicate the possibility of a chain stretch or jump in the chain link of the upper chain of timing. However, the code won't appear on its own, without additional information from other sensors (G4 and G40).

Testing can be a bit difficult since there are two pins for the connector and they perform different functions but the most effective method of testing it is to measure the resistance between the sensor and the ECU. When the sensor is fully functional, it should read around 1000 ohms. Look for evidence of coolant or oil in the connector bay if there are issues with this component.

2. Injectors

Yesterday, as i was accelerating off the highway paytoll at maximum speed I noticed a significant drop in power. It was like the engine had run out of gas. Or, my injectors were not firing. This morning i pull out the spark plugs. Three were drenched in gazoline, 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 out. The 4th one stays shut. 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 in another location.

I also tried to reset the PID with no success. The car will start when the G28 is disconnected, but it works fine when the G28 plugged in. However, the intermittent misfire problem continues to occur at higher RPM. The coolant sensor (G62), even when unplugged, still shows temperatures of -49c. I also noticed that the oil gauge in the cockpit shows 2 bar when the actual pressure is zero.

audi replacement car keys 'm not certain what to do, but i think i've pretty much ruled out everything else. I'm concerned that i may have missed something. Please let me know if you have any ideas! TIA!

3. Fuel Pump

The fuel pump on the g28 is activated by a signal sent from the RPM sensor. The GM-style sensor is identical to the G4 and both function in the 80 100, 200, UrS and RS2 cars so you can easily find one at a junkyard or from a parts store. It is simple to test them: simply switch your DMM into resistance mode and determine the distance between pins 1 and 2 (with the bump on the connector's edge facing up). They should be infinite ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY and ADU) engines have an ECU that must know the speed and position of the crankshaft to make decisions about timing of the fuel injectors, etc. In order to do this it makes use of 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 codes that could lead to an engine shutdown.

Some of the symptoms of a failed G28 sensor include an inaccurate gearbox rev counter the gears are shifting faster than normal, and/or a misfire when in gear. If you experience any of these issues it is most likely that your sensor is failing and needs replacing. The good news is that they are very affordable and readily available, especially in the case of an Bosch sensor, which is what ours are. Alternately, the GM version of this component is also a good option.

5. Tachometer

A faulty engine speed sensor could be a cause for many issues in your vehicle. It is an important part of the transmission of your Audi, as it transmits information to the ECU regarding how fast or slow the car's engine is turning. This sensor can cause the transmission to malfunction and other car components to be affected.

The G5 engine sensor is located at the outskirts of the transmission, just above the flywheel ring. It transmits a signal via gray wire to ECU pin T55/49. The ECU then uses and processes the signal to control fuel, timig and boost and then sends it on to the G5 Tachometer located in the instrument cluster. You can determine if the sensor is in 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 [79trace [79]), and between pin T6a/1 and pin T26a/12. You should see approximately 1000 ohms resistance between these two points. genuine audi key replacement is the same across the Audi 80-100-200-RS2 model, ranging from the 1985 MC all the way up to the 1997 UrS An and 1995 RS2 DU, so you might find them in wrecking yards.