Your Worst Nightmare About Audi G28 Relived
Your Worst Nightmare About Audi G28 Relived
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How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician shows you how to replace the G28 Engine Speed Sensor. This sensor is situated near the transmission's edge over the flywheel gear. It transmits a signal to the ECU through a grey wire T55/49, then to the tachometer in the instrument cluster.
1. Engine Speed Sensor
The grey wire is located on the outside of the transmission, above the flywheel ring. The sensor transmits signals through the grey wire to pin T55/49. The ECU utilizes this information to control fuel and boost. It also sends an indication to the G5 tachometer inside the instrument cluster.
The sensor is used to correlate the G40 Camshaft position Sensor. The ecu must know when the crankshaft is TDC and the location of the camshaft so it can start spark and injectors accordingly.
If this sensor fails, the ECU will throw a P00160 code which means the Crank Shaft and Intake Camshaft are not in sync and possibly indicating chain stretch or a jumped link on the upper timing chain. The code won't appear without the additional information provided by other sensors (G4 or G40).
It's a bit tricky to test since there are various pins on the connector and each one has different functions. The best way to do it is by measuring the resistance between the ECU and the sensor. If the sensor is operational, it should read around 1000 ohms. Examine for evidence of coolant or oil in the connector bay if you are experiencing issues with this part.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at full speed I noticed a massive drop in power. It was as if the engine had run out of gas. Or, my injectors were not firing. This morning i pull out the spark plugs, three were drenched with gazoline the fourth one was dry. When I crank the engine without sparks, i place a tissue on top of each injector hole and the 3 that were drenched in gazoline jump out but the 4th one stays shut. I tested the ground connection of ECU pins 14,30, and 48/55. I found zero ohm. I'm assuming the issue is in another place.
I also tried to reset the PID without success. The car can start when the G28 is disconnected and runs fine when it is plugged in but it still has the intermittent misfire issue at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature value of that is -49c even after unplugging it. I also noticed that the gauge for oil more info pressure in the cockpit shows 2 bar when the actual pressure is 0.0 when I crank up the engine.
I'm not sure what to do. I think I've eliminated everything else. I'm concerned that i may have missed something. If anyone has suggestions, please let me know! TIA!
3. Fuel Pump
The fuel pump in the g28 receives signals from the RPM sensor. The GM-style transmitter is identical to the G4 and both are used in the 80, 100 200, UrS and RS2 cars so you can easily find one at a wrecking yard or at a parts store. Testing them is easy by putting your DMM in resistance mode and take measurements between pins 1 (with the bump on the connector's side up) and 2 (2nd from left on the black end of the connector). They must be infinite Ohms.
4. ECU
Our 20vt turbo (3B, AAN, ABY and ADU) engines are equipped with an ECU that needs to be aware of the speed and position of the crankshaft in order to make decisions regarding timing of the fuel injectors, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 here to accomplish this. If either of these sensors go badly, you will see codes on the diagnostic scanner which can audi keys replacement lead to engine shutdown.
A malfunctioning G28 sensor can cause an inaccurate gearbox speed counter, a gearbox that shifts faster than normal, or a misfire in the gear. If you are experiencing any of these issues, it is most likely that your sensor is deteriorating and should be replaced. The good thing is that they are very cheap and easy to find, especially when you're looking at the Bosch unit like ours. If you prefer, GM's version of this part is a good option.
5. Tachometer
A damaged engine sensor could cause a variety of issues in your car. It's a crucial component of the transmission in your Audi more info because it relays information to the ECU regarding how fast or slowly the car's engine is turning. If this sensor fails, it will disrupt the performance of the transmission as well as the rest of the car's components.
The G5 engine speed sensor is located on the outside of the transmission just above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49 through an uncolored wire. click here The ECU uses this signal to regulate fuel and boost, and also to timigrate. It also relays it to the G5 Tachometer inside the instrument cluster. You can determine if the sensor is in failure by checking continuity from the sensor to the tachometer. You can also 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 detect a resistance of approximately 1000 ohms between these two points. This is a common feature across the Audi 80-100-200-RS2 model, ranging beginning with the 1985 MC and up to the 1997 UrS AN and 1995 RS2 DU, so you might find them in wrecking yards.