How The 10 Worst Audi G28-Related FAILS Of All Time Could've Been Prevented
How The 10 Worst Audi G28-Related FAILS Of All Time Could've Been Prevented
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How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician teaches you how to replace the G28 Engine Speed Sensor. The sensor is situated at the top of the transmission above the flywheel ring gear. It sends a signal to the ECU via the grey wire (T55/49), then to the tachometer located in the instrument cluster.
1. Engine Speed Sensor
Located on the edge of the transmission, above the flywheel ring gear G28 Engine Speed Sensor sends a signal to ECU pin T55/49 via the grey wire. The ECU then utilizes this information to regulate fuel, timig and boost. It also sends a signal to the G5 Tachometer located in the instrument cluster.
The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft is TDC and where the camshaft is located so that it can trigger spark and injectors according to the situation.
If this sensor fails, the ECU will show the P00160 error, which means the Crank Shaft and Intake Camshaft are out of sync and possibly indicating the chain stretching or a jump link on the upper timing chain. However, the code won't appear on its own, without additional information from other sensors (G4 and G40).
Testing can be a bit difficult because there are two pins for the connector and they serve different purposes but the most effective method of testing it is to measure the resistance between the sensor and the ECU. When the sensor is functional, it should read around 1000 ohms. If you are having problems with this sensor, look for signs of oil or coolant in the connector bay.
2. Injectors
Yesterday, while accelerating from the highway paytoll at a high speed I noticed a massive drop in power. It was as if the engine was running out of gas. Or, my injectors weren't firing. Today, i pulled out the spark plugs, three were soaked with gazoline and the fourth was dry. I put tissue over each injector hole and when I start the engine without sparks, the ones with gazoline jump right out. The 4th one remains closed. I tested the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ i get zero ohm. I think the issue is in another location.
I also tried to reset the PID but with no luck. The car will start when the G28 is unplugged, and it is running fine with the G28 connected. However, the intermittent misfire problem persists at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temp value -49c, even if I unplug it. I also noticed that the oil gauge in the cockpit shows 2 bar while the actual pressure is zero.
I'm not certain what to do, i believe that i've eliminated everything else. I'm concerned that i may have missed something. Let me know should you have any suggestions! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal by the RPM sensor. The GM-style transmitter functions similarly to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. It is easy to find the spare in a salvage shop or parts store. Test them out by putting your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's side up) and 2 (2nd from the left on the black end of the connector). They read more must be infinite Ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY ADU) engines requires to be aware of the position and speed the crankshaft to make decisions regarding timing of fuel injectors, etc. To do this, it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these go wrong, you will receive codes on the diagnostic scanner that can cause the engine to shut down.
A failing G28 sensor could result in an inaccurate gearbox speed counter or a gearbox that shifts more quickly than normal, and/or a misfire in gear. It is possible that the sensor is failing and needs to be replaced if you notice any of these signs. They're check here inexpensive and easy to locate especially if they're an Bosch model like ours. Alternately, GM's version this part would be an option.
5. Tachometer
A damaged engine sensor could cause a number of problems in your vehicle. It is an important part of the transmission in your Audi because it relays information to the ECU about how fast or slow the engine of the car is turning. This sensor could cause more info the transmission to fail and other components in the car to be affected.
The G5 engine sensor is located at the edge of transmission, above the flywheel ring. It sends a signal via audi a3 key replacement gray wire to ECU pin T55/49. The ECU uses this signal to control fuel and boost, as well as replacement key for audi a4 timig. It also relays it to the G5 Tachometer located in the instrument cluster. You can check the sensor for failure by examining the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should see the resistance to be around 1000 ohms between these two points. This part is common across the Audi 80-100-200-RS2 series, starting from the 1985 MC up to the 1997 UrS AN and the 1995 RS2 DU, so you might find them in wrecking yards.