20 Trailblazers Are Leading The Way In Audi G28

How to replace audi key fob an audi tt key fob not working G28 Engine Speed Sensor

In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. The sensor is located on the outside of the transmission, above the flywheel gear. It transmits a signal the ECU via an uncolored wire (T55/49) which is then sent to the tachometer located in the instrument cluster.

1. Engine Speed Sensor

Located on the edge of the transmission above the flywheel ring gear, the G28 Engine Speed Sensor sends a signal to ECU pin T55/49 via a grey wire. The ECU utilizes this information to control fuel and boost. It also sends an indicator to the G5 Tachometer located in the instrument cluster.

The sensor is used to correlate with the G40 Camshaft position Sensor. The ecu needs to know when the crankshaft reached TDC, and the location of the camshaft in order to activate the spark and injectors.

If this sensor fails, the ECU will display the P00160 error, which means the Crank Shaft and Intake Camshaft are not in sync and could indicate the chain stretching or a jump link on the upper chain of timing. The code won't appear without the additional information supplied by other sensors (G4 or G40).

Testing is a bit tricky because there are two pins for the connector and they have different functions but the most effective method of testing it is to measure the resistance between the sensor and the ECU. It should read about 1000 ohms when it is operating at its maximum. Look for evidence of coolant or oil in the connector bay if there are issues with this component.

2. Injectors

Yesterday, when i was accelerating to the fullest speed from highway paytoll i had an abrupt drop in power like the engine is running out of gas or injectors aren't firing anymore. I took out the spark plugs this morning, three were soaked in gasoline, and the fourth was unclean. I put a piece of tissue over each hole in the injector and when I start the engine with no sparks, the three with gazoline jump out. The fourth one remains shut. I checked the ground connection of ECU pins 14,30 and 48/55. I found zero ohm. I think the issue is in another location.

I also tried to reset the PID without success. The car will start when the G28 is not plugged in and runs fine when it is connected but it still is experiencing intermittent misfires at higher RPM. The coolant sensor (G62), even when unplugged, still shows an ice temperature of -49c. I also noticed that the oil gauge in the cockpit shows 2 bars while the actual pressure is 0.

I don't know what to do. I think I've ruled everything else out. However, i'm afraid that i might have missed something. Please let me know if you have any ideas! TIA!

3. Fuel Pump

The fuel pump of the g28 gets a signal from the RPM sensor. The GM-style transmitter is identical to the G4 sender and both work on the 80,100,200, UrS, and RS2 vehicles. It is easy to find a spare in a wrecking shop or parts store. It is easy to test them - just switch your DMM into resistance mode and measure the distance between pins 1 and 2 (with the bump at the connector's end facing up). They should be infinite Ohms.

4. ECU

The ECU in our 20vt turbo (3B AAN ABY) engines requires to know the position and speed the crankshaft in order to make a decision about timing of fuel injectors, etc. In order to do this it uses a Crank Position Sensor (G4) and an Engine Speed Sensor (G28). If either of these goes badly, you will see codes on the diagnostic scanner that could cause engine shut down.

A malfunctioning G28 sensor could result in an inaccurate gearbox speed counter or a gearbox that shifts more quickly than normal, or a misfire while in the gear. It is probable that your sensor is failing and needs to be replaced if you encounter any of these symptoms. They're cheap and easy to find particularly if they're an Bosch model like ours. Alternatively, GM's version of this part would be an excellent choice.

5. Tachometer

A damaged engine sensor could cause a myriad of issues in your vehicle. It is an important part of the transmission of your Audi A3 Spare Key, as it transmits information to the ECU on how fast or slowly the car's engine is turning. This sensor can cause the transmission to malfunction and other car components to be affected.

The G5 engine speed sensor is located on the edge of the transmission, above the flywheel ring gear and sends a signal to the ECU at pin T55/49 through an uncolored wire. The ECU is then able to process this signal to control fuel, timig and boost and then sends it on to the G5 tachometer in the instrument cluster. You can check for sensor failure by checking continuity from the sensor to the tachometer. Additionally, you can check continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79trace [79]), and between pin T6a/1 and pin T26a/12. You should see approximately 1000 ohms of resistance between those points. This is the same across the audi spare key cost 80-100-200-RS2 model, ranging beginning with the 1985 MC and up to the 1997 UrS An and 1995 RS2 DU, so you might find good ones in wrecking yards.