Year/Model
1999 BMW 528I Wagon
Problem
Transmission Fault light
History
Customer arrived in shop originally with brake lights stuck on. Checked vehicle computer and found faulty switch. Replaced switch with no problems for one month. Customer comes back to shop with radio not functioning and transmission fault light on.
Diagnostic
Plugged in vehicle scanner and found code for brake light switch short. Checked wiring at switch with no issues. Found strange problem where brake lights would stay on and radio not functioning. Checked vehicle computer and found no communication with many vehicle system such as abs, srs, traction control, radio, wipers.
Common problems with BMW is to have a fault in the CAN Bus system. The CAN bus is a communication system within the vehicle that allows for data transfer between different components. It is similar to a highway. If there is a traffic jam or component that is shorting and constantly transmitting data, no other system will be allowed to communicate with each other.
The way to figure out which one is jamming the system is to find the hub and disconnect one at a time. Once disconnected you need to restart the car and see if its functioning again. The hub for the CAN Bus is usually behind the glove box. The wires are connected to a piece of metal that has multiple tabs on them. The wire is solid white with red stripes and yellow dots.
We disconnected each lead and tested the system with no change. Usually we find one that is the problem and easily fixed. Since so many systems are not connected we had to move on. We them proceeded to test the power going to the modules. We found intermittent power at each. Tracing further back to the ignition system we found that jiggling the wiring at the ignition switch would cause the systems to come back online. We found the electrical part of the ignition to be the problem. Our part number was 61 32 6 901 961. Sorry that i do not have a picture attached.
Repair
Removed and replaced ignition switch electrical assembly. Tested vehicle, ok at this time.
Disclaimer
Use
this at your own risk, only reporting my own findings. If you found
this helpful, feel free to donate so I can keep posting up more useful
tips. If this was helpful, give it a quick post below to show your interest
Friday, April 26, 2013
Friday, January 4, 2013
2006 Audi A4 Quattro 2.0 Turbo FSI P0299 Underboost
Year/Model
2006 Audi A4 Quattro 2.0 37,000 miles
Problem
P0299 Under boost condition
History
Owner tried to smog vehicle and when tech connected obd2 found code for P0299.
Diagnostic
Customer brought vehicle to our shop and noted no drive ability issues. We connected our VAG-COM to the car and found this code stored in the vehicle. The instant data showed that this happened at 2800 rpm and the frequency was only once. Upon our test drive, boost was fairly normal and was kicking in around the 3000-3200 rpm range. We then used the graph feature of the VAG-COM and checked measuring block 115 which had actual and specified boost conditions in mBar. Upon driving, we found that the car was providing boost but was 500 mBar under the specified value.
The next step was to smoke the vehicle and check for any vacuum hose leaks. The big difference was that from the 1.8t engine to the 2.0t engine is that they got rid of many vacuum hoses and updated to electrical controlled valves. This is a good and bad as its much easier to replace and cracked hoses are less frequent. We found no leaks at this time which showed us that the leak was not venting to the atmosphere. On the older 1.8 the diverter valve would either go bad or the vacuum hose going to the valve would crack. We decided to pull the valve and check.
Results shown below.
Repair
The diverter valve is located in the front of the turbo manifold on the passenger side right behind the radiator. The best way to access was from below after the splash shield is removed. There is one electrical connector attached. Sorry but i have no picture of the actual location. Here is the Audi print. It is part number 15 in the picture and is held in via 3 allen screws.
Upon removal of the part we found that it was the older style valve and was never updated from Audi. The valve moves in and out as boost increase or decreases to adjust for any variance. As you can see in the picture the main diaphram is made of a rubber material and has torn. This tear causes a minor leak in the boost causing the vehicle to not reach specified boost. The picture below shows the wear on the rubber as well as the old original part.
As you can see Audi recognized this problem and has updated the part and superseded the part # 06H 145 710D. By the time you read this, they might superseded it again. As you can see the valve now offers a shroud around the moving diaphragm in case there is any debris that may be inside.
Upon replacement, we cleared the vehicle check engine light codes and graphed our data again. On our test drive from partial throttle to WOT we found the difference between actual and specified values to be only 5-30 mBar which is acceptable. The customer was instructed to drive the vehicle for a few days and return if the light returns. If the light does not return, the customer was instructed to return to the smog station for a retest.
Disclaimer
Use this at your own risk, only reporting my own findings. If you found this helpful, feel free to donate so I can keep posting up more useful tips. If this was helpful, give it a quick post below, makes me feel better :)
2006 Audi A4 Quattro 2.0 37,000 miles
Problem
P0299 Under boost condition
History
Owner tried to smog vehicle and when tech connected obd2 found code for P0299.
Diagnostic
Customer brought vehicle to our shop and noted no drive ability issues. We connected our VAG-COM to the car and found this code stored in the vehicle. The instant data showed that this happened at 2800 rpm and the frequency was only once. Upon our test drive, boost was fairly normal and was kicking in around the 3000-3200 rpm range. We then used the graph feature of the VAG-COM and checked measuring block 115 which had actual and specified boost conditions in mBar. Upon driving, we found that the car was providing boost but was 500 mBar under the specified value.
The next step was to smoke the vehicle and check for any vacuum hose leaks. The big difference was that from the 1.8t engine to the 2.0t engine is that they got rid of many vacuum hoses and updated to electrical controlled valves. This is a good and bad as its much easier to replace and cracked hoses are less frequent. We found no leaks at this time which showed us that the leak was not venting to the atmosphere. On the older 1.8 the diverter valve would either go bad or the vacuum hose going to the valve would crack. We decided to pull the valve and check.
Results shown below.
Repair
The diverter valve is located in the front of the turbo manifold on the passenger side right behind the radiator. The best way to access was from below after the splash shield is removed. There is one electrical connector attached. Sorry but i have no picture of the actual location. Here is the Audi print. It is part number 15 in the picture and is held in via 3 allen screws.
Upon removal of the part we found that it was the older style valve and was never updated from Audi. The valve moves in and out as boost increase or decreases to adjust for any variance. As you can see in the picture the main diaphram is made of a rubber material and has torn. This tear causes a minor leak in the boost causing the vehicle to not reach specified boost. The picture below shows the wear on the rubber as well as the old original part.
As you can see Audi recognized this problem and has updated the part and superseded the part # 06H 145 710D. By the time you read this, they might superseded it again. As you can see the valve now offers a shroud around the moving diaphragm in case there is any debris that may be inside.
Upon replacement, we cleared the vehicle check engine light codes and graphed our data again. On our test drive from partial throttle to WOT we found the difference between actual and specified values to be only 5-30 mBar which is acceptable. The customer was instructed to drive the vehicle for a few days and return if the light returns. If the light does not return, the customer was instructed to return to the smog station for a retest.
Disclaimer
Use this at your own risk, only reporting my own findings. If you found this helpful, feel free to donate so I can keep posting up more useful tips. If this was helpful, give it a quick post below, makes me feel better :)
Tuesday, May 1, 2012
2000 VW Volkswagen Jetta No OBD II Link
Year/Model
2000 VW Jetta
Problem
No link to OBD II
History
Owner tried to smog vehicle and when tech connected obd2 scanner to vehicle, would receive notice of no link active.
Diagnostic
Customer brought vehicle to our shop. We tried to connect VAG com scanner to vehicle and found no link either. Checked all fuses, everything ok. Saw vehicle was wired up with aftermarket stereo. Removed after market stereo to inspect wiring. Found radio was providing power to the KBus line in the vehicle and was jamming the system. Disconnected all aftermarket wiring and was then able to scan vehicle for codes. Smogged vehicle.
Repair
Disconnected radio from the KBus wire as see in the picture. The radio wiring harness wire was blue with a white stripe. The vehicle wiring was the black plug with the gray with the white stripe. I left the blue wire hooked up for the aftermarket power antenna wire. Checked the system to see if it can scan, ok. The VAG com did show a fault for no stereo but that is because the aftermarket can not interact with the BUS system
Just disconnect the blue/white wire or which ever one corresponds to the wiring position shown in the plug.
Disclaimer
Use this at your own risk, only reporting my own findings. If you found this helpful, feel free to donate so i can keep posting up more useful tips. If this was helpful, give it a quick post below, makes me feel better :)
2000 VW Jetta
Problem
No link to OBD II
History
Owner tried to smog vehicle and when tech connected obd2 scanner to vehicle, would receive notice of no link active.
Diagnostic
Customer brought vehicle to our shop. We tried to connect VAG com scanner to vehicle and found no link either. Checked all fuses, everything ok. Saw vehicle was wired up with aftermarket stereo. Removed after market stereo to inspect wiring. Found radio was providing power to the KBus line in the vehicle and was jamming the system. Disconnected all aftermarket wiring and was then able to scan vehicle for codes. Smogged vehicle.
Repair
Disconnected radio from the KBus wire as see in the picture. The radio wiring harness wire was blue with a white stripe. The vehicle wiring was the black plug with the gray with the white stripe. I left the blue wire hooked up for the aftermarket power antenna wire. Checked the system to see if it can scan, ok. The VAG com did show a fault for no stereo but that is because the aftermarket can not interact with the BUS system
Disclaimer
Use this at your own risk, only reporting my own findings. If you found this helpful, feel free to donate so i can keep posting up more useful tips. If this was helpful, give it a quick post below, makes me feel better :)
Subscribe to:
Posts (Atom)