How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. The sensor is situated on the edge of the transmission, above the flywheel ring gear. It sends a message to the ECU through an uncolored wire T55/49, then to the tachometer located on the instrument cluster.
1. Engine Speed Sensor
The sensor is located at the edge of the transmission just above the flywheel ring gear G28 Engine Speed Sensor sends a signal to ECU pin T55/49 via a grey wire. The ECU then uses this information to control fuel, timig and boost. It also sends signals to the G5 tachometer inside the instrument cluster.
The sensor is used to correlate with the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft has reached TDC and also the position of the camshaft, to trigger the spark and injectors.
If this sensor fails the ECU will throw the P00160 error, which means the Crank Shaft and Intake Camshaft are not in sync, possibly indicating chain stretch or a jumped link on the upper chain of timing. However, the code won't appear on its own without additional information from other sensors (G4 and G40).
Testing is a bit challenging because there are two pins for the connector and they serve different purposes however the best method of testing it is to measure the resistance between the sensor and the ECU. It should read approximately 1000 ohms if the sensor is at full operation. If you're having issues with this sensor, look for signs of oil or coolant in the connector bay.
2. Injectors
Yesterday, while accelerating from the highway paytoll at full speed I noticed a massive decrease in power. It was as if the engine was running out of gas. Or my injectors were not firing. I pulled out the spark plugs this morning, three were soaked with gasoline and the fourth was unclean. When i crank the engine with no sparks i put tissue on the top of each hole in the injector and the 3 that were drenched in gazoline leap out, however the 4th stays shut. I checked the ground connection of ECU pins 14,30, and 48/55. I got 0ohm. I'm assuming the issue is somewhere else.
I also tried to reset the PID but with no luck. The car will start when the G28 is disconnected, but it is running fine with the G28 connected. However the intermittent misfire issue persists at higher RPM. The coolant temperature sensor (G62) shows the wrong temp value -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows click here 2 bar when the actual pressure is zero.
I don't know what to do. I feel like i've pretty much all other possibilities out. I'm concerned that i may have missed something. Let me know If you have any suggestions! TIA!
3. Fuel Pump
The fuel pump of the g28 receives a signal 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 which is why you can easily locate one at a salvage yard or from a parts store. It is easy 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 up). They should be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY and ADU) engines have an ECU that must know the position and speed of the crankshaft in order to make a decision about fuel injector timing etc. In order to do this it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these go badly, you will see codes on the diagnostic scanner which can lead to engine shutdown.
A damaged G28 sensor could result in an inaccurate speed counter for the gearbox and a gearbox which shifts more quickly than normal, or a misfire audi car keys replacement in the gear. It is likely that your sensor is failing and needs to be replaced if you experience any of these symptoms. The good news is they are very cheap and easy to find, especially if you're looking at a Bosch model, like ours. Alternatively, GM's version of this part would be a good option.
5. Tachometer
A damaged engine sensor could cause a myriad of issues in your car. It is an important part of the transmission in your Audi since it sends information to the ECU about how fast or slowly the engine is spinning. This sensor could cause the transmission to malfunction and other components in the car to be affected.
The G5 engine speed sensor is situated on the outside of the transmission above the flywheel ring gear. It sends a signal directly to the ECU at website pin T55/49, via an uncolored wire. The ECU uses this signal to regulate fuel and replacement key for audi a4 boost, and also to timigrate. It also relays it to the G5 Tachometer in instrument cluster. You can check the sensor for any failure by checking the continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. You should see a resistance of approximately 1000 ohms between these points. This is the same across the Audi 80-100-200-RS2 series, starting beginning with the 1985 MC and up to the audi car keys 1997 UrS An and 1995 RS2 Du You may also find good ones in wrecking yards.