14 Smart Strategies To Spend Extra Audi G28 Budget

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 on the outside of the transmission over the flywheel gear. It transmits a signal the ECU via an uncolored wire (T55/49) which is then sent to the tachometer within the instrument cluster.

1. Engine Speed Sensor

It is located on the outside of the transmission, above the flywheel ring gear, the G28 Engine Speed Sensor sends an electrical signal to ECU pin T55/49 via a grey wire. The ECU then uses this information to control the boost, fuel, and timig. It also sends an alert to the G5 Tachometer in instrument cluster.

The sensor is used to connect the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft is TDC and the location of the camshaft so it can trigger spark and injectors in the right way.

If this sensor fails the ECU will throw the P00160 error, which means the Crank Shaft and Intake Camshaft are not in sync and possibly indicating the chain is stretched or a jump link on the upper timing chain. However the code will not be displayed on its own without additional information from other sensors (G4 and G40).

Testing can be a bit difficult since there are two pins for the connector and they have different functions however the best method of testing it is by measuring resistance between the sensor and the ECU. It should read around 1000 ohms if the sensor is at full operation. Look for signs of coolant, or oil in the connector bay if you have problems with this part.

2. Injectors

Yesterday accelerating full speed from highway paytoll, i experienced massive power loss like the engine is running out of gas or the injectors are not firing anymore. Today, i pulled out the spark plugs, three were drenched in gazoline, the fourth was dry. I put tissue over each injector hole and when i turn the engine on without sparks, the 3 with gazoline jump right out. The 4th one stays shut. 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 PID but without success. The car can start when the G28 is unplugged and it runs perfectly when it is connected, but read more still is experiencing intermittent misfires at higher RPM. The coolant sensor (G62) even if it is not plugged in, shows an ice temperature of -49c. Also, i noticed that the gauge for oil pressure in the cockpit shows 2 bar when the actual pressure is 0.0 when I crank up the engine.

I'm not certain what to do, but i feel i have pretty much completely ruled out all other possibilities. I'm afraid i may have missed something. Let me know If you have any suggestions! TIA!

3. Fuel Pump

The fuel pump of the g28 gets a signal from the RPM sensor. The GM-style transmitter is more info identical to the G4 sender and works on the 80,100,200, UrS, and RS2 vehicles. You can easily find the spare in a salvage shop or parts store. Testing them is easy to do - just put your DMM in resistance mode and measure between pins 1 (with the bump here 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

Our 20vt turbo (3B AAN, ABY and ADU) engines have an ECU that must know the speed and position of the crankshaft in order to make decisions regarding fuel injector timing etc. To accomplish this, it makes use of a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If get more info either of these goes wrong, you will receive codes on the diagnostic scanner which could cause engine shut down.

Some of the symptoms of a failing G28 sensor include an inaccurate rev counter in the gearbox and gears that shift faster than normal and/or misfiring when you are in gear. If you experience any of these problems, it is likely your sensor is deteriorating and requires replacement. They are cheap and easy-to-find especially if they're an Bosch unit like ours. Alternately, the GM version of this part is also a great option.

5. Tachometer

A malfunctioning engine sensor can cause a myriad of issues in your audi a4 spare key vehicle. It's a vital component of the Audi's transmission as it sends information to the ECU about how fast or slow the car's crankshaft is turning. This sensor can cause the transmission to malfunction and other car components to be affected.

The G5 engine sensor is located near the edge of the transmission, over the flywheel ring. It transmits an electrical signal through an uncolored wire to the ECU pin T55/49. The ECU is then able to process this signal to regulate fuel, timig and boost as well as transmitting it to the G5 Tachometer located in the instrument cluster. You can test for sensor failure by examining the continuity from the sensor to the tachometer. Also, you can verify continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]), and between pin T6a/1 as well as pin T26a/12. It should show approximately 1000 ohms of resistance between those points. This is a common feature across the Audi 80-100-200-RS2 range, from the 1985 MC all the way up to the 1997 UrS An and 1995 RS2 DU You may also find good ones in wrecking yards.