10 Wrong Answers To Common Audi G28 Questions Do You Know The Correct Answers?
10 Wrong Answers To Common Audi G28 Questions Do You Know The Correct Answers?
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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. This sensor is situated near the transmission's edge just above the flywheel gear. It sends a message to the ECU via the grey wire T55/49 and then to the tachometer located on the instrument cluster.
1. Engine Speed Sensor
It is located on the outside of the transmission just above the flywheel ring gear the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 through an uncolored wire. The ECU then uses this information to control the flow of fuel, timig and boost. It also sends signals to the G5 tachometer in the instrument cluster.
The sensor is used to link with the G40 Camshaft position Sensor. The ecu needs to be aware of when the crankshaft has reached TDC, and where the camshaft lies to trigger the spark and injectors.
If this sensor fails the ECU will display a P00160 code which means the Crank Shaft and Intake Camshaft are out of sync and could indicate chain stretch or a jumped link on the upper chain of timing. The code won't show without the additional information provided by other sensors (G4 or G40).
It is a little tricky to test as there are various connector pins, and they all have different functions. The most effective method to test it is by measuring the resistance between the ECU and the sensor. When the sensor is fully functional, it should read around 1000 ohms. Examine for signs of coolant, or oil in the connector bay if you have issues with this component.
2. Injectors
Yesterday accelerating full speed from highway paytoll i had a big cut in power as if the engine was running out of gas or injectors are not firing any more. I pulled out the spark plugs this morning and found that 3 were soaked in gasoline, and the 4th was dry. When i crank the engine without sparks, I put a piece of tissue on the top of each of the injector holes and the 3 drenched with gazoline pop out, but the 4th stay shut. I checked the ground connection on ECU pins 14/55, 30/55 and 48/55. I get 0ohm. Therefore, i think the issue is in another place.
I also tried to reset the PID without success. The car will start when the G28 is disconnected and runs fine when it is plugged in, but still is experiencing intermittent misfires at higher RPM. The coolant sensor (G62), even here if it is not plugged in, shows an ice temperature of -49c. Also, i noticed that the oil pressure gauge in the cockpit shows 2 bar while 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 any ideas please chime in! TIA!
3. Fuel website Pump
The fuel more info pump of the g28 gets a signal from 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 so you can easily find one at a wrecking yard or at a parts store. It is simple to test them - just switch your DMM into resistance mode and measure the distance between pins 1 and 2 check here (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 are equipped with an ECU that needs to be aware of the speed and position of the crankshaft to make a decision about timing of the fuel injectors, etc. 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 that can lead to engine shutdown.
A damaged G28 sensor can cause an inaccurate speed counter for your gearbox and a gearbox which shifts faster than normal, or an unfire when in the gear. It is likely that the sensor is failing and needs to be replaced if you encounter any of these symptoms. They are cheap and easy-to-find, especially if they're a Bosch sensor like ours. If you prefer, GM's version of this part is an excellent choice.
5. Tachometer
A malfunctioning engine sensor can cause a myriad of issues within your vehicle. It is an important part of the transmission in your Audi since it sends information to the ECU regarding how fast or slow the car's engine is turning. This sensor could cause the transmission to malfunction and other car components to be affected.
The G5 engine sensor is located at the edge of the transmission, over the flywheel ring. It transmits a signal via an uncolored wire to the ECU pin T55/49. The ECU utilizes this signal to control the flow of fuel and boost as well as timig. It also transmits 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 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 detect an average resistance of 1000 ohms between these two points. This read more is a common feature 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 some good ones in wrecking yards.