How to Replace an Audi Q7 Replacement Key G28 Engine Speed Sensor
(Image: https://g28carkeys.co.uk/wp-content/uploads/2023/10/Kia-Motors-New-2021.png)Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. This sensor is situated on the outside of the transmission just above the flywheel gear. It sends a signal to the ECU via an uncolored wire (T55/49), then to the tachometer in the instrument cluster.
1. Engine Speed Sensor
The grey wire is situated at the edges of the transmission, above the flywheel ring. The sensor sends signals through the grey wire to pin T55/49. The ECU then utilizes this information to regulate the flow of fuel, timig and boost. It also sends a signal to the G5 tachometer in the instrument cluster.
The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu must be aware when the crankshaft is TDC and where the camshaft is so it can activate spark and injectors according to the situation.
If this sensor fails, the ECU will display a P00160 error message. This indicates that the Crank Shaft is out of alignment with the Intake Camshaft. It could also be a sign of a chain stretch or a jumpy chain link in the upper chain of timing. However, the code won't appear 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 serve different purposes however the best method of testing 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're experiencing issues with this sensor, look for evidence of coolant or oil in the connector bay.
2. Injectors
Yesterday, when accelerating from highway paytoll at maximum speed I noticed a massive drop in power. It was as if the engine was running out of gas. Or my injectors weren't firing. This morning i pull out the spark plugs. Three were drenched in gazoline, the 4th one was dry. I put tissue over each hole in the injector and when I start the engine without sparks, the 3 that have gazoline pop right out. The 4th one stays closed. I tested the ground connection of ECU pins 14,30 and 48/55. I found zero ohm. I think the issue is somewhere else.
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 issue continues to occur at higher RPM. The temperature sensor for the coolant (G62) shows the wrong temperature of -49c even when i unplug it. I also noticed that the oil gauge in the cockpit shows 2 bars while the actual pressure is 0.
I'm not sure what to do. I feel like i've pretty much ruled everything else out. I'm afraid i may have missed something. Please let me know should you have any suggestions! TIA!
3. Fuel Pump
The fuel pump in the g28 gets a signal from the RPM sensor. The GM-style sender is identical to the G4 and they both work in the 80 100 200, UrS and RS2 cars so you can easily find one at a junkyard or at a parts store. Testing them is easy by putting your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's side up) and 2 (2nd from the left on the black connector's end). They should be infinite ohms.
4. ECU
Our 20vt turbo (3B AAN, ABY and ADU) engines have an ECU that has to be aware of the speed and position of the crankshaft in order to make a decision about fuel injector timing etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If either of these goes wrong, you will receive codes on the diagnostic scanner that can lead to engine shutdown.
A failing G28 sensor could result in an inaccurate speed counter for your gearbox or a gearbox that shifts more quickly than normal, and/or an unfire when in gear. It is possible that your sensor is failing and needs to be replaced if you experience any of these signs. They're cheap and easy to find especially in the case of a Bosch model like ours. If you prefer, GM's version of this part would be an option.
5. Tachometer
A malfunctioning engine speed sensor could be the reason behind many issues with your vehicle. It is a crucial part of the audi key copy's transmission because it communicates to the ECU about how fast or slow the car's crankshaft is turning. This sensor could cause the transmission to fail and Audi A3 Spare Key other car components to be affected.
(Image: https://g28carkeys.co.uk/wp-content/uploads/2023/10/Citroen.png)The G5 engine speed sensor is located at the outside of the transmission, above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49 via an uncolored wire. The ECU uses this signal to regulate the flow of fuel and boost as well as timig. It also relays it to the G5 Tachometer in instrument cluster. You can check 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 on pin T6a/1 (trace [79]) as well as between T6a/1, and the instrument cluster pin T26a/12. You should detect a resistance of approximately 1000 ohms between these points. This part is common across the audi connect key 80-100-200-RS2 series, starting from the 1985 MC up to the 1997 UrS AN and the 1995 RS2 DU So, you may find them in wrecking yards.
