How to Replace an audi key programmer G28 Engine Speed Sensor
In this video, Charles the humble mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is located near the transmission's edge just above the flywheel gear. It sends a message to the ECU via the grey wire T55/49 and then to the tachometer on the instrument cluster.
1. Engine Speed Sensor
Located on the edge of the transmission just above the flywheel ring gear the G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 using the grey wire. The ECU then utilizes this information to regulate the flow of fuel, timig and boost. It also sends signals 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 must know when the crankshaft reached TDC and also where the camshaft lies to trigger the spark and injectors.
If this sensor fails, the ECU will display a P00160 error code. This means that the Crank Shaft is out of sync with the Intake Camshaft. It could also be a sign of a chain stretch or a jump in the chain link of the upper chain. However, the code won't be displayed on its own without additional information from other sensors (G4 and G40).
Testing can be a bit difficult as there are two different connector pins, and they serve different purposes however the best method to test it is to measure resistance between the sensor and the ECU. If the sensor is functional, it should read around 1000 ohms. If you're having issues with this component, look for signs of oil or coolant in the connector bay.
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 running out of gas or the injectors aren't firing anymore. Today, i pulled out the spark plugs, 3 were drenched in gazoline, the fourth one was dry. I put a piece of tissue over each injector hole, and when i start the engine with no sparks, the ones with gazoline jump out. The fourth one remains closed. I tried to test the ground connections of ECU pins 14,30, and 48/55. I got zero ohm. I'm assuming that the issue is elsewhere.
(Image: https://g28carkeys.co.uk/wp-content/uploads/2023/10/Subaru-logo.png)I also tried to reset the PID but without success. The car will start when the G28 is disconnected, but it runs fine with the G28 connected. However, the intermittent misfire problem still occurs at higher RPM. The coolant sensor (G62), even if it is not plugged in, shows a temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bars but the actual pressure is zero.
I'm not sure what to do. I think I've all other possibilities out. I'm concerned that i may have missed something. Let me know If you have any suggestions! TIA!
(Image: https://g28carkeys.co.uk/wp-content/uploads/2023/11/key-from-new-car-2021-08-29-05-15-15-utc-min-scaled.jpg)3. Fuel Pump
The fuel pump in the g28 gets a signal from the RPM sensor. The GM-style sender is the same as the G4 and both function in the 80 100, 200, UrS and RS2 cars so you can easily find one at a junkyard or at a parts store. Test them out to do - just put your DMM in resistance mode and measure between pins 1 (with the bump on the connector's side up) and 2 (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 ADU) engines must know both the speed and position of the crankshaft to determine timing of fuel injectors, etc. To do this, it utilizes a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these sensors go badly, you will see codes on the diagnostic scanner which could cause engine shut down.
The signs of a malfunctioning G28 sensor are an inaccurate rev counter for the gearbox the gears are shifting faster than normal, and/or a misfire when you're in gear. If you experience any of these issues, it is likely that your sensor is failing and should be replaced. They're cheap and easy to find, especially when they're a Bosch unit like ours. You can also choose the GM version of this unit is also a great option.
5. Tachometer
A failing engine speed sensor could be the reason behind many issues in your car. It's a crucial component of the transmission in your audi key fobs, as it transmits information to the ECU regarding how fast or slowly the car's engine is turning. This sensor could cause the transmission to fail and other components of the car to be affected.
The G5 engine speed sensor is located on the edge of the transmission just above the flywheel ring gear and transmits a signal to the ECU at pin T55/49 through an uncolored wire. The ECU is then able to process the signal to control fuel, timig, and boost, and also sends it on to the G5 tachometer 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. You should detect the resistance to be around 1000 ohms in these areas. This is a common feature across the audi replacement key tt replacement car key audi audi new key (www.youtube.Com) 80-100-200-RS2 model, ranging from the 1985 MC all the way up to the 1997 UrS AN and 1995 RS2 Du You may also find some good ones in wrecking yards.