Audi G28 10 Things I'd Like To Have Known Sooner
Audi G28 10 Things I'd Like To Have Known Sooner
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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. The sensor is located at the edge of transmission over the flywheel gear. It transmits a signal to the ECU via an uncolored wire (T55/49), then to the tachometer within the instrument cluster.
1. Engine Speed Sensor
Located on the edge of the transmission, above the flywheel ring gear the G28 Engine Speed Sensor sends signals to ECU pin T55/49 through the grey wire. The ECU uses this information to regulate boost and fuel. It also sends a signal to the G5 Tachometer located in the instrument cluster.
The sensor serves as a reference to correlate with the G40 Camshaft Position Sensor. The ecu must be aware when the crankshaft is TDC and the location of the camshaft so it can start spark and injectors in the right way.
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 indicate the possibility of a chain stretch or jumped chain link in the upper timing chain. However, the code won't appear on its own without additional information from other sensors (G4 and G40).
It can be a bit difficult to test as there are several pins on the connector and they all have different functions. The best way to do it is to measure the resistance between the ECU and the sensor. If the sensor is operational, it should be reading around 1000 ohms. Examine for evidence of coolant or oil in the connector bay if there are issues with this part.
2. Injectors
Yesterday, when accelerating from highway paytoll at full speed I noticed a massive decrease in power. It was as if the engine had run out of gas. Or my injectors weren't firing. Today, i pulled out the spark plugs, 3 were drenched with gazoline the fourth one was dry. I placed a tissue over each injector hole, and when I start the engine with no sparks, the 3 with gazoline jump out. The fourth one remains shut. I checked the ground connection of ECU pins 14,30, and 48/55. I got zero ohm. So i assume the problem is somewhere else.
I also tried to reset PID without success. The car will start if the G28 is unplugged and is running fine when it is connected but it still is experiencing intermittent misfires at higher RPM. The coolant sensor (G62), even when unplugged, still shows an ice temperature of -49c. I also noticed that the oil pressure gauge in the cockpit shows 2 bar when the actual pressure is 0.0 when i rev the engine.
I'm not certain what to do, but i feel i have pretty much ruled out 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 can be activated by a signal sent from the RPM sensor. The GM-style sender is the same as 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. Testing them is easy - put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector end up) and 2 (2nd from the left on the black connector's end). They must be infinite Ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY and ADU) engines are equipped with an ECU that needs to click here know the speed and position of the crankshaft to make decisions regarding timing of the fuel injector, for example. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If either of these sensors go badly, you will see codes on the diagnostic scanner that could cause engine shut down.
A damaged G28 sensor could cause an inaccurate speed counter for your gearbox, a gearbox that shifts more quickly than normal, and/or a misfire while in the gear. If you experience any of these problems, it is likely that your sensor is deteriorating and needs replacing. They're cheap and easy to find particularly if they're an Bosch sensor like ours. Alternatively, GM's version of this component is an excellent choice.
5. Tachometer
A failing engine speed sensor could be the reason behind a slew of issues with read more your car. It's a crucial component of the transmission in your Audi since it sends audi car key information to the ECU on how fast or slow the engine is spinning. This sensor can cause the transmission to fail and other car components to be affected.
The G5 engine sensor is located at the edge of transmission, audi a1 car key above the flywheel ring. It sends a signal via a gray wire to the ECU pin T55/49. The ECU utilizes this signal to regulate the flow of fuel and boost and also timig. It also transmits it to the G5 Tachometer located in the instrument cluster. You can determine if the sensor is in failure by examining the continuity from the sensor to the tachometer. Additionally, you can verify continuity audi car keys replacement 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 observe approximately 1000 ohms resistance between those points. This is a standard component across the Audi 80 100, 200, UrS and RS2 range from 1985 MC through the 1997 UrS AAN and 1995 RS2 ADU so good ones might be availble in wrecking yards.