Your Worst Nightmare About Audi G28 Bring To Life
Your Worst Nightmare About Audi G28 Bring To Life
Blog Article
How to Replace an Audi G28 Engine Speed Sensor
Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. The sensor is situated near the edges of the transmission just above the flywheel ring gear. It sends a signal to the ECU via a grey wire (T55/49), then to the tachometer in the instrument cluster.
1. Engine Speed Sensor
The sensor is located at the edge of the transmission above the flywheel ring gear G28 Engine Speed Sensor sends signals to ECU pin T55/49 through an uncolored wire. The ECU then uses this information to control the flow of fuel, timig and boost. It also sends an indication to the G5 tachometer in the instrument cluster.
The sensor is used as a reference for comparing with the G40 Camshaft Position Sensor. The ecu needs to know when the crankshaft is TDC and the location of the camshaft so it can activate spark and injectors accordingly.
If this sensor fails the ECU will show an error code P00160 which indicates that the Crank Shaft and Intake Camshaft aren't in sync and could indicate chain stretch or a jumped link on the upper timing chain. However, the code won't appear on its own without additional information from other sensors (G4 and G40).
Testing is a bit challenging as there are two different pins for the connector and they serve different purposes but the most effective method of testing it is to measure resistance between the sensor and the ECU. When the sensor is fully operational, it should be reading around 1000 ohms. If you're experiencing issues with this sensor, look for evidence of coolant or oil in the connector bay.
2. Injectors
Yesterday accelerating full speed from highway paytoll, I experienced a big cut in power like the engine is out of gas or the injectors aren't firing anymore. Today, i pulled out the spark plugs, three were drenched in gazoline, the 4th one was dry. I put a piece of tissue over each injector hole, and when I turn the engine on without sparks, the 3 with gazoline jump out. The 4th one stays closed. I inspected the ground connection on ECU pins 14/55/30/55/48/55/14/55/48/ i get 0ohm. I assume that get more info the problem is elsewhere.
I also tried to reset the PID with no success. The car will start when the G28 is unplugged, and it is running fine with the G28 plugged in. However, the intermittent misfire problem continues to occur at higher RPM. The coolant temperature sensor (G62) shows the wrong temp value -49c even when i unplug it. I also noticed that the oil gauge here in the cockpit shows 2 bar while the actual pressure is 0.
I'm not sure what to do, i feel i audi car keys have pretty much ruled out everything else. I'm afraid i may have missed something. Please let me know if you have any ideas! TIA!
3. Fuel Pump
The fuel pump in the g28 is activated by a signal sent from the RPM sensor. The GM-style transmitter is identical to the G4 sender, and more info both operate on the 80,100,200, UrS, and RS2 vehicles. It is easy to find a spare in a wrecking shop or parts store. Test them out to do - just put your DMM in resistance mode and measure the resistance between pins 1 (with the bump on the connector's end up) and check here 2 (2nd from left on the black connector's side). They must be infinite Ohms.
4. ECU
The ECU in our 20vt turbo (3B AAN ABY ADU) engines must be aware of the speed and position of the crankshaft to determine fuel injector timing, etc. It uses a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If either of these sensors go wrong, you will receive codes on the diagnostic scanner that can cause the engine to shut down.
The signs of a failing G28 sensor are an inaccurate rev counter for the gearbox, gears shifting quicker than normal and/or a misfire when you are in gear. It is probable that the sensor is failing and needs to be replaced if you experience any of these symptoms. They're inexpensive and easy to locate particularly in the case of an Bosch sensor like ours. If you prefer, GM's version of this component is an option.
5. Tachometer
A malfunctioning engine sensor can cause a myriad of issues in your car. It's a crucial component of the transmission of your Audi since it sends information to the ECU about how fast or slowly the car's engine is turning. This sensor can cause the transmission to malfunction and other components in the car to be affected.
The G5 engine sensor is located at the outskirts of the transmission, just above the flywheel ring. It transmits a signal via gray wire to ECU pin T55/49. The ECU utilizes this signal to regulate fuel and boost, and also timig. It also relays it to the G5 Tachometer in instrument cluster. You can test for sensor failure by examining the continuity of the sensor to the tachometer. You can also examine the continuity between pins 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 a resistance of approximately 1000 ohms between these two points. This part is common 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, so you might find some good ones in wrecking yards.