5 Laws That Anyone Working In Audi G28 Should Be Aware Of
5 Laws That Anyone Working In Audi G28 Should Be Aware Of
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How to Replace an Audi G28 Engine Speed Sensor
In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. This sensor is situated on the outside of the transmission over the flywheel gear. It transmits a signal the ECU via the grey wire (T55/49) and then to the tachometer located in the instrument cluster.
1. Engine Speed Sensor
Located on the edge of the transmission just above the flywheel ring gear the G28 Engine Speed Sensor sends signals to ECU pin T55/49 through the grey wire. The ECU utilizes this information to control the amount of fuel and boost. It also sends an alert to the G5 Tachometer in 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 the position of the camshaft, so that it can activate the spark and injectors.
If this sensor fails, the ECU will display a P00160 error code. This indicates that the Crank Shaft is not in line with the Intake Camshaft. It could also be a sign of a chain stretch or a jump in the chain link of the upper timing chain. However, the error code won't be displayed on its own without additional information from other sensors (G4 and G40).
It's a bit tricky to test as there are several connector pins, and each has its own functions. The best way to do it is by measuring the resistance between the ECU and the sensor. It should read approximately 1000 ohms when it is operating at its maximum. If you are having problems with this sensor, look for evidence of oil or coolant in the connector bay.
2. Injectors
Yesterday, while accelerating from the highway paytoll at full speed I noticed a significant reduction in power. It was as if the engine had run out of gas. Or my injectors were not firing. I took out the spark plugs this morning, 3 were soaked with gasoline and the fourth was dry. When i crank the engine with no sparks i put tissue on the top of each of the injector holes and the 3 that were drenched in gazoline pop out, but the 4th one stays closed. I checked the ground connection of ECU pins 14,30, and 48/55. I found zero ohm. I think the issue is elsewhere.
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 plugged in. However, the intermittent misfire problem persists 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 while the actual pressure is zero.
I'm not sure what to do, i believe that i've completely ruled out all other possibilities. But i am afraid I might have missed something. If anyone has suggestions, please share them! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal sent from the RPM sensor. The GM-style transmitter is identical to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. It is easy to find a spare in a wrecking shop or 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 at the connector's end facing up). They should be infinite Ohms.
4. ECU
Our 20vt turbo (3B, AAN, ABY and ADU) engines are equipped with an ECU that has to be aware of the speed and position of the crankshaft to make decisions regarding timing of the fuel injectors, etc. To do this, it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor audi a3 replacement key (G28). If either of these sensors go wrong, you will receive codes on the diagnostic scanner which could cause engine shut down.
Some of the signs of a failed G28 sensor are 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 problems, it is likely that your sensor is going bad and requires replacement. They are cheap and easy-to-find especially if they're a Bosch sensor like ours. Alternatively, GM's version of this component is an excellent choice.
5. Tachometer
A damaged engine sensor could cause a variety of issues within your vehicle. It's an replacement car key audi essential component of the Audi's transmission as it sends information to the ECU about how fast or slow the vehicle's crankshaft is spinning. If this sensor fails, it could cause problems for the transmission, as well as the rest of the car's components.
The G5 engine speed sensor is situated on the outside of click here the transmission above the flywheel ring gear. It sends a signal to the ECU at click here pin T55/49 via a grey wire. The ECU then uses and processes this signal to control fuel, timig and boost, and also sends it on to the G5 Tachometer located in the instrument cluster. You can determine if here the sensor is in failure by examining the continuity from the sensor to the tachometer. Additionally, you can examine the continuity between pins 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 those points. This is a typical component across the Audi 80 100, 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU. Good parts could be found in wrecking yards.