Your Worst Nightmare About Audi G28 It's Coming To Life
Your Worst Nightmare About Audi G28 It's Coming To Life
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How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician teaches you how to replace the G28 Engine Speed Sensor. This sensor is located near the transmission's edge just above the flywheel gear. It transmits a signal to the ECU via a grey wire T55/49, then to the tachometer on the instrument cluster.
1. Engine Speed Sensor
The grey wire is located on the edge of transmission, above the flywheel ring. The sensor sends a signal via the grey wire to pin T55/49. The ECU uses this information to regulate boost and fuel. It also sends an alert to the G5 Tachometer located in the instrument cluster.
The sensor is used 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 trigger spark and injectors in the right way.
If this sensor fails the ECU will show an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are out of sync and possibly indicating the chain is stretched or a jump link on the upper timing chain. However, the error code won't be displayed on its own without additional information from other sensors (G4 and G40).
Testing can be a bit difficult because there are two connector pins and they perform different functions but the best method to test it is by measuring resistance between the sensor and the ECU. It should read approximately 1000 ohms when it is at full operation. If you are having problems with this component, look for evidence of coolant or oil in the connector bay.
2. Injectors
Yesterday, while accelerating at full speed from the highway paytoll, I experienced a big cut in power as if the engine was running out of gas or the injectors aren't firing anymore. I took out the spark plugs this morning and found that 3 were drenched in gasoline and the 4th was dry. When I crank the engine, there are no sparks, i place a tissue on the top of each of the injector holes, the 3 drenched with gazoline jump out but the 4th stay closed. I tried to test the ground connections of ECU pins 14,30 and 48/55. I got 0ohm. So i assume the problem is somewhere else.
I also tried to reset the PID with no success. The car will start when audi lost key the G28 is unplugged, and it runs fine with the G28 connected. However the intermittent misfire issue persists at higher RPM. The temperature sensor for coolant (G62) shows the wrong temp value -49c even when i unplug it. 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 crank up the engine.
I don't know what to do. I feel like i've pretty much all other possibilities out. I'm concerned that i may have missed audi keys something. Let me know If you have any suggestions! TIA!
3. Fuel Pump
The fuel pump in the g28 can be activated by a signal sent by the RPM sensor. The GM-style transmitter is identical to the G4 sender, and both operate on the 80,100,200, UrS, and RS2 vehicles. It is easy to find a spare in a wrecking shop or a parts store. Testing them is easy by putting here your DMM in resistance mode and measure between pins 1 (with the bump on the connector's side up) and 2 audi a1 key (2nd from the left on the black connector's side). They should be infinite Ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY) engines requires to know both the speed and position of the crankshaft to determine fuel injector timing, etc. It makes use of a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If either of these sensors go wrong, you will receive codes check here on the diagnostic scanner which can lead to engine shutdown.
A malfunctioning G28 sensor could cause an inaccurate gearbox speed counter, a gearbox that shifts faster than normal, and/or an unfire when in gear. It is possible that the sensor is failing and requires to be replaced if you notice any of these symptoms. They're inexpensive and easy to locate particularly if they're a Bosch unit like ours. Alternatively, the GM version of this unit is also a good option.
5. Tachometer
A failing engine speed sensor could be the cause of many issues with your car. It's a crucial component of the transmission of your Audi, as it transmits information to the ECU regarding how fast or slow the engine of the car is spinning. This sensor can cause the transmission to fail and other components of the car to be affected.
The G5 engine speed sensor is located on the outside of the transmission, above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49 through a grey wire. The ECU then processes this signal to regulate fuel, timig, and boost, and also sends it on to the G5 Tachometer located in the instrument cluster. You can test for sensor failure by examining the continuity of the sensor to the tachometer. Additionally, you can check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]) and between pin T6a/1 as well as pin T26a/12. It should show approximately 1000 ohms of 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 could be available in wrecking yards.