The Most Pervasive Issues In Audi G28

How to Replace an new audi keys 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 over the flywheel gear. It transmits a signal to the ECU through a grey wire T55/49, then to the tachometer on 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 a grey wire. The ECU utilizes this information to control boost and fuel. It also sends an indicator to the G5 Tachometer in instrument cluster.

The sensor is used as a reference for comparing with the G40 Camshaft Position Sensor. The ecu has to know when the crankshaft has reached TDC and also the location of the camshaft so that it can activate the spark and injectors.

If this sensor fails to function, the ECU will display a P00160 error message. This means that the Crank Shaft is not in line with the Intake Camshaft. It could also indicate an issue with the chain or a jumpy chain link in the upper timing chain. The code will not appear without the additional information supplied by other sensors (G4 or G40).

Testing is a bit challenging because there are two pins for the connector and they perform different functions however the best method to test it is to measure the resistance between the sensor and the ECU. It should read around 1000 ohms when the sensor is operating at its maximum. If you're having issues with this part, check for evidence of coolant or oil in the connector bay.

2. Injectors

Yesterday, while accelerating at full speed from the highway paytoll i had a big cut in power as if the engine was running out of gas or injectors aren't firing anymore. Today, i pulled out the spark plugs. Three were soaked with gazoline and the fourth one was dry. When I crank the engine without sparks, i place a tissue on the top of each of the injector holes, the 3 drenched with gazoline jump out but the 4th stays closed. I tested the ground connection on ECU pins 14/55,30/55 and 48/55 I get 0ohm. I'm assuming the issue is elsewhere.

I also tried to reset the PID without success. The audi car key replacement cost will start when the G28 is disconnected, but it is running fine with the G28 plugged in. However the intermittent misfire issue persists at higher RPM. The coolant sensor (G62), even when it is unplugged, shows temperatures of -49c. I also noticed that the oil pressure gauge in the cockpit is showing 2 bar while the actual pressure is 0.0 when I crank up the engine.

I'm not sure what to do, as i feel i have pretty much ruled out everything else. I'm worried that i might have missed something. Please let me know if you have any ideas! TIA!

3. Fuel Pump

The fuel pump in the g28 receives signals from the RPM sensor. The GM-style transmitter is identical to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. You can easily find an extra in a wrecking shop or parts store. Test them out by putting your DMM in resistance mode and measure between pins 1 (with the bump on the connector end up) and 2 (2nd from left on the black connector's side). They must be infinite Ohms.

4. ECU

Our 20vt turbo (3B AAN, ABY and ADU) engines are equipped with an ECU that has to know the speed and position of the crankshaft in order to make a decision about timing of the fuel injectors, etc. To accomplish this, it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If you have a problem with either one of these, the diagnostic scanner will display codes that could lead to an engine shutdown.

A damaged G28 sensor can cause an inaccurate speed counter for the gearbox and a gearbox which shifts more quickly than normal, and/or a misfire in the gear. If you are experiencing any of these issues it is likely your sensor is failing and needs replacing. The good news is that they are very cheap and easily accessible, especially if you're looking at a Bosch sensor, which is what we have. Alternatively, the GM version of this component is also a great option.

5. Tachometer

A failing engine sensor could cause a number of problems in your vehicle. It's an essential component of your Replacement Audi A4 Key's transmission, since it relays information to the ECU about how fast or slow the vehicle's crankshaft is spinning. This sensor can cause the transmission to malfunction and other components in the audi car key replacement cost to be affected.

The G5 engine sensor is located at the edge of the transmission, over the flywheel ring. It transmits a signal via a gray wire to the ECU pin T55/49. The ECU is then able to process this signal to regulate the flow of fuel, timig and boost, and also transmitting it to the G5 Tachometer located in the instrument cluster. You can test the sensor for any failure by checking the continuity between it and the tachometer, between ECU pin T55/49 and the instrument cluster connection to pin T6a/1 (trace [79trace [79]) and between pin T6a/1 and the instrument cluster pin T26a/12. You should see a resistance of approximately 1000 ohms between these two points. This is the same across the replacement key audi 80-100-200-RS2 range, from the 1985 MC all the way up to the 1997 UrS AN and the 1995 RS2 Du You may also find good ones in wrecking yards.