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 outside of the transmission, above the flywheel gear. It transmits a signal to the ECU via an uncolored wire T55/49, then to the tachometer in 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 an electrical signal to ECU pin T55/49 through an uncolored wire. The ECU utilizes this information to control boost and fuel. just click the up coming internet page sends an indication to the G5 tachometer in the instrument cluster.
The sensor is used to link the G40 Camshaft position Sensor. The ecu must know when the crankshaft reached TDC, and where the camshaft lies so that it can activate the spark and injectors.
If this sensor fails when it fails, the ECU will display a P00160 error message. This means that the Crank Shaft is not in alignment with the Intake Camshaft. It could also be a sign of an issue with the chain or a jump in the chain link of the upper 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 have different functions however the best method of testing it is to measure the resistance between the sensor and the ECU. It should read approximately 1000 ohms when it is operating at its maximum. If you are having problems with this part, check for signs of coolant or oil in the connector bay.
2. Injectors
Yesterday, while accelerating from the highway paytoll at a high speed, i noticed a huge reduction in power. It was as if the engine had run out of gas. Or, my injectors were not firing. In the morning, i removed the spark plugs, three were drenched in gazoline, the fourth one was dry. When I crank the engine, there are no sparks, i place a tissue on the top of each hole in the injector and the 3 drenched with gazoline pop out, but the 4th stays shut. I checked 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 somewhere else.
I also tried to reset PID but without success. The car will start when the G28 is not plugged in and runs fine when it is plugged in but it still has the intermittent misfire issue at higher RPM. The coolant sensor (G62), even when unplugged, still shows a temperature of -49c. Also i noticed that the gauge for oil pressure in the cockpit is showing 2 bar when the actual pressure is 0.0 when i rev the engine.
I'm not sure what to do, as i feel i have pretty much ruled out everything else. But i'm worried that I may have missed something. Let just click the up coming internet page know If you have any suggestions! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal sent by the RPM sensor. The GM-style sensor is identical to the G4 and they both work in the 80 100 200, UrS and RS2 cars which is why you can easily locate one at a wrecking yard or at a parts store. It is easy to test them: simply switch your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector end facing up). They must be infinite Ohms.
4. ECU
Our 20vt turbo (3B, AAN, ABY and ADU) engines have an ECU that has to know the position and speed of the crankshaft to make decisions regarding fuel injector timing etc. In order to do this it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you have a problem with either of these sensors, the diagnostic scanner will display codes that could lead to an engine shut down.
A damaged G28 sensor could cause an inaccurate speed counter for your gearbox, a gearbox that shifts more quickly than normal, or a misfire in the gear. If you experience any of these problems, it is likely that your sensor is failing and requires replacement. They're cheap and easy to find, especially in the case of a Bosch sensor like ours. You can also choose the GM version of this unit is also a good choice.
5. Tachometer
A malfunctioning engine sensor can cause a variety of issues in your vehicle. It's a vital 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 affect the performance of the transmission and the other car's components.
The G5 engine speed sensor is located on the edge of the transmission just above the flywheel ring gear. It transmits a signal to the ECU at pin T55/49, via a grey wire. The ECU uses this signal to control fuel and boost, as well as timig. It also sends 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. Also, you can check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]) and between pin T6a/1 and pin T26a/12. You should see approximately 1000 ohms of resistance between those points. This part is common across the Audi 80-100-200-RS2 range, from the 1985 MC all the way up to the 1997 UrS AN and 1995 RS2 Du, so you might find good ones in wrecking yards.