How to Replace an audi key replacement G28 Engine Speed Sensor
In this video Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. This sensor is located on the edge of the transmission just above the flywheel ring gear. It sends a message to the ECU via a grey wire T55/49, then to the tachometer in the instrument cluster.
1. Engine Speed Sensor
The sensor is located at the edge of the transmission above the flywheel ring gear the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 using an uncolored wire. The ECU uses this information to regulate fuel and boost. It also sends an indication to the G5 Tachometer in instrument cluster.
The sensor serves as a reference for comparing with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft reached TDC and also the location of the camshaft in order to activate the spark and injectors.
If this sensor fails, the ECU will throw an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are out of sync and could indicate the chain stretching or a jump link on the upper chain of timing. 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 since there are different pins on the connector and each one has different functions. The best method for doing this is by measuring the resistance between the ECU and the sensor. It should read approximately 1000 ohms if the sensor is operating at its maximum. If you're experiencing issues with this part, check for signs of coolant or oil in the connector bay.
2. Injectors
Yesterday, as i was accelerating off the highway paytoll at a high speed, i noticed a huge drop in power. It was like the engine was running out of gas. Or, my injectors weren't firing. I took out the spark plugs this morning, 3 were soaked in gasoline, and the fourth was unclean. When I crank the engine, there are no sparks, I put a piece of tissue on top of each injector hole and the 3 drenched with gazoline jump out but the 4th stays shut. I tried to test the ground connections of ECU pins 14,30, and 48/55. I found 0ohm. I assume that the problem is elsewhere.
I also tried to reset the PID but with no luck. The car is able to start when the G28 is disconnected and is running fine when it is connected, but still has the intermittent misfire issue at higher RPM. The temperature sensor for coolant (G62) shows the wrong temperature of -49c even when i unplug it. I also noticed that the gauge for oil pressure in the cockpit is showing 2 bar, whereas the actual pressure is 0.0 when i rev the engine.
I don't know what to do. I believe that I've ruled everything else out. I'm afraid i may have missed something. Let me know if you have any ideas! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal from the RPM sensor. The GM-style sender is the same as the G4 and both are used in the 80 100 200, UrS and RS2 cars so you can easily find one at a junkyard or in a local parts store. It is simple to test them - just switch your DMM into resistance mode and test the distance between pins 1 and 2 (with the bump at the connector's end facing upwards). They should be infinite ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY ADU) engines requires to know both the position and speed the crankshaft to determine fuel injector timing, etc. To accomplish this, it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these goes bad you will get codes on the diagnostic scanner which can cause the engine to shut down.
Some of the signs of a failed G28 sensor include an inaccurate rev counter for the gearbox, gears shifting quicker than normal, and/or a misfire when you are in gear. If you are experiencing any of these issues it is likely that your sensor is failing and should be replaced. The good news is they are quite affordable and readily available particularly when you're looking at the Bosch model, which is what we have. Alternatively, GM's version of this part is a good option.
5. Tachometer
A failing engine sensor could cause a myriad of issues in your car. It's a crucial component of the transmission of your audi key fob since it sends information to the ECU regarding how fast or slow the engine is turning. If the sensor fails, it can disrupt the performance of the transmission, as well as the other car's components.
The G5 engine sensor is located near the edge of transmission, above the flywheel ring. It sends an electrical signal through 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 relays it to the G5 Tachometer inside the instrument cluster. You can test the sensor Audi keys replacement (bysee3.com) for failure by checking continuity between it and the tachometer, between the ECU pin T55/49 and the instrument cluster connection on pin T6a/1 (trace [79trace [79]) and between T6a/1 and the instrument cluster pin T26a/12. It should show approximately 1000 ohms of resistance between those points. This is a common feature across the audi replacement key cost uk 80-100-200-RS2 model, ranging from the 1985 MC up to the 1997 UrS AN and the 1995 RS2 DU You may also find some good ones in wrecking yards.