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 located at the top of the transmission just above the flywheel ring gear. It transmits a signal to the ECU via the grey wire T55/49 and 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 G28 Engine Speed Sensor sends a signal to ECU pin T55/49 via a grey wire. The ECU uses this information to regulate boost and fuel. It also sends an indication to the G5 Tachometer located in the instrument cluster.
The sensor serves as a reference point to connect with the G40 Camshaft Position Sensor. The ecu needs to be aware of when the crankshaft has reached TDC, and the position of the camshaft, to trigger 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 stretching or a jump link on the upper chain of timing. However the code will not appear on its own, without additional information from other sensors (G4 and G40).
Testing can be a bit difficult since there are two connector pins, and they have different functions however the best method to test it is to measure resistance between the sensor and the ECU. It should read about 1000 ohms if the sensor is in full operation. Look for evidence of coolant or oil in the connector bay if you are experiencing problems with this part.
2. Injectors
Yesterday, when i was accelerating to the fullest speed from highway paytoll, i experienced an abrupt drop in power like the engine is out of gas or the injectors aren't firing anymore. This morning i pull out the spark plugs. Three were drenched with gazoline the 4th one 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 inspected the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ I got zero Ohm. I assume that the problem is in another location.
I also tried to reset the PID with no success. The car is able to start when the G28 is disconnected and is running fine when it is connected however it has intermittent misfire issues at higher RPM. The coolant sensor (G62), even when unplugged, still shows an ice temperature of -49c. Also, i noticed that the oil pressure gauge in the cockpit is showing 2 bar when the actual pressure is 0.0 when I crank up the engine.
I'm not sure what to do. I think I've ruled click here everything else out. I'm afraid i may have missed something. If anyone has suggestions, please share them! TIA!
3. Fuel Pump
The fuel pump of the g28 gets a signal from the RPM sensor. The GM-style sensor is identical to the G4 and both function in the 80, 100 200, UrS and RS2 cars so you can easily find one at a salvage yard or at a parts store. It is simple to test them - 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 side). They should 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 accomplish this, it makes use of here a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you encounter a problem with either of these, the diagnostic scanner will display codes that could cause an engine shut down.
Some of the audi replacement car keys symptoms of a failing G28 sensor are an inaccurate rev counter for the gearbox and gears that shift faster than normal and/or misfiring when in gear. If you experience any of these problems, it is how much is a replacement audi key likely that your sensor is failing and requires replacement. They're inexpensive and easy to locate particularly when they're a Bosch unit like ours. Alternately, GM's version this part is an excellent choice.
5. Tachometer
A damaged engine sensor could cause a variety of issues in your car. It's an essential component of the transmission check here in your Audi since it sends information to the ECU about how fast or slowly the 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 outskirts of transmission, above the flywheel ring. It transmits signals via gray wire to ECU pin T55/49. The ECU uses this signal to control fuel and boost, and also timig. It also sends it to the G5 Tachometer located in the instrument cluster. You can test the sensor for failure by checking continuity between it and the tachometer. You can also check continuity between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. There should be the resistance to be around 1000 ohms between these points. This is the same across the Audi 80-100-200-RS2 range, beginning with the 1985 MC and up to the 1997 UrS AN and 1995 RS2 Du So, you may find good ones in wrecking yards.