Inspection Tips For Chain-Driven Water Pumps
Why Alternators Are Subject To Ripple Voltage
Exhaust Gas Recirculation Operation and Diagnostics
Clearing Up Import Coolant Confusion
Inspection Tips For Chain-Driven Water Pumps
Why Alternators Are Subject To Ripple Voltage
Exhaust Gas Recirculation Operation and Diagnostics
Clearing Up Import Coolant Confusion
Gasoline Direct Injection: Total System Diagnostics
Sponsored By Carter Fuel Systems
Modern gasoline direct injection (GDI) engines have two fuel pump opportunities. You still have an electric pump in the tank, but a high-pressure fuel pump is on the engine. These two pumps work in unison, so the correct quantity of fuel is injected directly into the cylinder. If either pump can’t generate the pressure or volume commanded by the engine management system, it will cause driveability issues. In a 45-minute webinar, the experts from Carter Engineered Fuel Pumps will train you on how to diagnose the entire fuel system of a GDI vehicle.
Speakers Julio Ortego, Engineering Manager, Repair Products Andrew Markel, Director of Technical Content, ShopOwner
Sponsored By Carter Fuel Systems
ShopOwner includes technical and management content and is free to download and read.
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Underhood Service targets repair shops that derive 50 percent or more of their revenue from the service and repair of under-the-hood systems. The expanding amount of knowledge and capital needed to keep up with technological advances has led these shop owners to concentrate on underhood systems, while also offering preventive maintenance services on most major vehicle systems. By subscribing, you’ll receive the ShopOwner digital edition magazine (12 times/year) featuring articles from Underhood Service and the Underhood Service eNewsletter (twice weekly). Access to digital editions, contests, news, and more are ready for you today!
Underhood Service targets repair shops that derive 50 percent or more of their revenue from the service and repair of under-the-hood systems. The expanding amount of knowledge and capital needed to keep up with technological advances has led these shop owners to concentrate on underhood systems, while also offering preventive maintenance services on most major vehicle systems. By subscribing, you’ll receive the ShopOwner digital edition magazine (12 times/year) featuring articles from Underhood Service and the Underhood Service eNewsletter (twice weekly). Access to digital editions, contests, news, and more are ready for you today!
ByUnderhood Service Staff Writers on Oct 7, 2022
ByUnderhood Service Staff Writers on Oct 6, 2022
High underhood temps, increased power demands and vibration can damage alternators or starters. Sponsored by ACDelco.
Don’t settle for “almost” - it matters where the engine is manufactured or remanufactured. Sponsored by ACDelco.
Brake pads are thoroughly developed to produce the best result. This video is sponsored by ZF Aftermarket.
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What could intermittent or erratic wheel speed sensor codes mean for wheel bearings? Sponsored by BCA Bearings by NTN.
CC:Advertisement A customer comes into your shop. They say that their ABS light is on and it usually comes on after one or two minutes of driving. You scan the vehicle and there are codes for a wheel speed sensor that say either intermittent or erratic. These can vary depending on the manufacturer and the type of code. What do these codes and that customer symptom have to do with the wheel bearing? Well, the reality of it is on most modern vehicles, the encoder, tone ring, or reluctor is part of the wheel bearing hub unit or part of the inboard seal on most wheel bearings on late model vehicles.AdvertisementWhen this is there, well, when the bearing has in play, run out, or other issues, that tone ring can become unseated and it changes the air gap for the sensor. When the air gap changes for the sensor, this changes the signal or wave form coming back to the hydraulic control unit for the ABS. If it cannot get a consistent signal, it’s going to set that code. Does it really matter? It’s just a land one wheel? Yes, because those systems actually check the four wheels, and if it sees behavior that is erratic or not normal, it sets that code. So how do you test to see if it actually is the hub unit? If you’re dealing with an active wheel speed sensor, it means that this seal actually has magnets that alter polarity going back and forth, back and forth, so it’s able to sense those magnets going by the wheel speed sensor head. When this happens, it registers the speed of the wheel or a degree of movement.AdvertisementIf you’re dealing with an older style passive wheel speed sensor, in those cases, you’re actually dealing with AC voltage being generated by a magnetic wheel speed sensor and window pans inside of something around the axle or part of the hub itself. In those cases, that sensor does not become active until the vehicle reaches five to seven miles per hour. But active is what you’re going to be dealing with on a lot of late model vehicles. How do you test this? Well, you can use a scope. You can also use your scan tool to look at the different speeds and compare all four wheel speeds to see if something drops out when you’re making a corner or a turn, and this will confirm that there might be an issue with the hub unit. After that, perform a visual inspection. Take the wheel and make sure that there’s no in play. Then if possible, and you may have to remove the axle, look at the hub unit on the vehicle when it’s attached to the knuckle. If you see large pieces of debris stuck to it, try cleaning it and then going for a test drive. But if this seal is broken out of the lip, it needs to be replaced. There’s no way you can service just the seal.AdvertisementJust keep that in mind when you’re dealing with one of these vehicles and a customer complaint that their ABS light is on and an erratic or intermittent wheel speed sensor code. I’m Andrew Markel. Thank you very much. This video is sponsored by BCA Bearings by NTN
A customer comes into your shop. They say that their ABS light is on and it usually comes on after one or two minutes of driving. You scan the vehicle and there are codes for a wheel speed sensor that say either intermittent or erratic. These can vary depending on the manufacturer and the type of code. What do these codes and that customer symptom have to do with the wheel bearing? Well, the reality of it is on most modern vehicles, the encoder, tone ring, or reluctor is part of the wheel bearing hub unit or part of the inboard seal on most wheel bearings on late model vehicles.
When this is there, well, when the bearing has in play, run out, or other issues, that tone ring can become unseated and it changes the air gap for the sensor. When the air gap changes for the sensor, this changes the signal or wave form coming back to the hydraulic control unit for the ABS. If it cannot get a consistent signal, it’s going to set that code.
Does it really matter? It’s just a land one wheel? Yes, because those systems actually check the four wheels, and if it sees behavior that is erratic or not normal, it sets that code. So how do you test to see if it actually is the hub unit? If you’re dealing with an active wheel speed sensor, it means that this seal actually has magnets that alter polarity going back and forth, back and forth, so it’s able to sense those magnets going by the wheel speed sensor head. When this happens, it registers the speed of the wheel or a degree of movement.
If you’re dealing with an older style passive wheel speed sensor, in those cases, you’re actually dealing with AC voltage being generated by a magnetic wheel speed sensor and window pans inside of something around the axle or part of the hub itself. In those cases, that sensor does not become active until the vehicle reaches five to seven miles per hour. But active is what you’re going to be dealing with on a lot of late model vehicles.
How do you test this? Well, you can use a scope. You can also use your scan tool to look at the different speeds and compare all four wheel speeds to see if something drops out when you’re making a corner or a turn, and this will confirm that there might be an issue with the hub unit. After that, perform a visual inspection. Take the wheel and make sure that there’s no in play. Then if possible, and you may have to remove the axle, look at the hub unit on the vehicle when it’s attached to the knuckle. If you see large pieces of debris stuck to it, try cleaning it and then going for a test drive. But if this seal is broken out of the lip, it needs to be replaced. There’s no way you can service just the seal.
Just keep that in mind when you’re dealing with one of these vehicles and a customer complaint that their ABS light is on and an erratic or intermittent wheel speed sensor code. I’m Andrew Markel. Thank you very much.
This video is sponsored by BCA Bearings by NTN
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Technical resources to help diagnose and repair engine-related service issues.