Audi G28 10 Things I'd Like To Have Known Earlier
Audi G28 10 Things I'd Like To Have Known Earlier
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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. The sensor is located at the edge of transmission just above the flywheel gear. It transmits a signal to the ECU through a grey wire T55/49, then to the tachometer located on the instrument cluster.
1. Engine Speed Sensor
The grey wire is located at the edges of the transmission, just above the flywheel ring. The sensor sends a signal via the grey wire to pin T55/49. The ECU then utilizes this information to regulate fuel, timig and boost. It also sends signals to the G5 Tachometer located in the instrument cluster.
The sensor is used to link with the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft reached TDC and also the position of the camshaft, so that it can activate the spark and injectors.
If this sensor fails the ECU will display an error code P00160 which indicates that the Crank Shaft and Intake Camshaft aren't in sync and could indicate the chain is stretched or a jump link on the upper timing chain. The code won't appear without the additional information supplied by other sensors (G4 or G40).
Testing is a bit tricky since there are two pins for the connector and they have different functions but the best method to test it is to measure the resistance between the sensor and the ECU. It should read around 1000 ohms when it is in full operation. Look for evidence of coolant or oil in the connector bay if there are issues with this part.
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. Today, i pulled out the spark plugs, three were drenched in gazoline, the fourth one was dry. I placed a tissue over each injector hole and when I start the engine with no sparks, the three with gazoline jump right out. The 4th one remains closed. I checked the ground connection on ECU pins 14/55,30/55 and 48/55 I get 0ohm. I think the issue is somewhere else.
I also tried to reset the PID without success. The car will start when the G28 is unplugged, and it runs fine with the G28 connected. However, the intermittent misfire problem continues to occur at higher RPM. The temperature sensor for coolant (G62) replacement key for audi a4 shows the wrong temp value that is -49c even after unplugging it. I also noticed that the oil pressure gauge in the cockpit is showing 2 bar when the actual pressure is 0.0 when i rev the engine.
I'm not certain what to do, as i think i've pretty much eliminated everything else. I'm concerned that i may have missed something. If anyone has any suggestions, please let me know! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal sent from the RPM here sensor. The GM-style transmitter functions similarly to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. You can easily locate the spare in a salvage shop or a parts store. It is easy to test them: simply put your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump on the connector's edge facing upwards). They should be infinite Ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY) engines must be aware of the position and speed the crankshaft to determine timing of the fuel injector, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to accomplish this. If you encounter a problem with either of these, the diagnostic scanner will display the codes that could trigger the engine shutting down.
A failing G28 sensor could cause an inaccurate speed counter for your gearbox and a gearbox which shifts faster than normal, and/or a misfire while in the gear. If you have any of these issues it is likely your sensor is deteriorating and requires replacement. The good thing is that they are very cheap and easily accessible particularly if you're looking at an Bosch sensor, like ours. You can also choose the GM version of this part is also a good option.
5. Tachometer
A failing replacement car key audi engine sensor could cause a number of problems within your vehicle. It's an essential component of the transmission in your Audi since it sends information to the ECU about how fast or slowly the engine is spinning. 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 transmission, 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 fuel and boost, as well as timig. It also sends it to the G5 Tachometer in instrument cluster. You can test for sensor failure by examining the continuity from the sensor to the tachometer. Additionally, website you can verify 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. It should show approximately 1000 ohms here of resistance between these two points. This is a typical part that is found across the Audi 80, 100 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU so good ones might be availble in wrecking yards.