hello. i am new to this and i was just wondering about my new truck the light was on when i bought it and they said they had it all checked out. i was wondering how to reset the ecm on that truck
- posted
18 years ago
hello. i am new to this and i was just wondering about my new truck the light was on when i bought it and they said they had it all checked out. i was wondering how to reset the ecm on that truck
You should have made them fix it. Resetting the computer won't do it You need to have the code checked and fix the failing component. These are usually expensive. Your ABS system is not working when the light is on.
we checked out the abs system today in school. we are in the truck and transport mechanic course taking abs and we couldnt find anything wrong with the system. the truck only has front wheel abs and we were told that if the back wheels spin more than three revolutions with the brakes on it will throw a code and you will need to reset the abs module.
Lets see, the ABS system consists of the wheel sensors, hydraulic modulator, ABS solenoids, electronic brake control module, master cylinder, half a dozen or so wiring harnesses and more. You checked them all out and determined they were all in perfect order without a manual or scanner. Boy that must be a great school with many crystal balls. You need to have the ABS codes read out with a scanner capable of reading them. This means you will need to go to a dealer or a good service shop that has the capability.....
And to answer your question about resetting the light. There are two ways,
Whoever told you that your truck only has front wheel ABS does not know what they are talking about. It is true that you will get codes if you have the truck on a hoist and you spin up just the rear wheels while the fronts are not moving. The reasons for this should be self evident.
Ian
Please educate an inyerested non-mechanic, and tell me the advantges and disadvantages of an ABS braking system.
Be careful with that question. To some the whole ABS issue can take on an almost religious fervor, like air bags or DRL's. To me ABS is as follows:
Pro:
- The ability to retain greater directional control in some circumstances while panic braking. Shorter stopping distances under SOME conditions.
Con:
- Considerable added complexity & repair expense down the road. Increased stopping distances under SOME OTHER conditions.
A lot depends on the skill level of the driver. Me, I have ABS, don't mind it, but wont sink $$$$ into repairing it when it fails & leaves me with 'standard' brakes.
Regards, Al.
Are you asking for an explanation of why ABS codes will be set if you spin the rear wheels only while the vehicle is on a hoist? Is so, it's fairly simple. The computer sees the two front wheels as "locked" up.....or no speed signals from the front wheels when there should be. Remember, the computer cannot tell that you have the vehicle up in the air.
With vehicles that have traction control....you can't spin up the wheels on the hoist...as the vehicle tries to prevent the two drive wheels from spinning. It "thinks" the front wheels have no traction as it sees the rear wheels stationary while the front wheels are spinning. Fortunately, there are either Traction control disable buttons, or you can simply put the park brake on.
Some of these features can make diagnosis difficult. Now a lot of the vehicles have electronic throttles. It's impossible to "blip" the throttle from the engine compartment. So it becomes a two man job, which is ridiculous. If there is some enterprising person out there.....design and build a jumper harness that would go between the engine harness and the electronic throttle with a spring loaded lever that would allow you to "manually" move the throttle from the engine compartment. I'd buy one. Hell, maybe I ought to design one.
Ian
Thanks Al for your informative comments.
Is there any way to tell if a car has the ABS system installed? Something I can look for under the hood perhaps?
My age, bad back, and arthritis would prevent me from lying down and sticking my head under the car.
Guess best thing is Not to Panic when car skids, right? and steer into the skid direction?
Hey, shiden_kai, thanks for comments, but all I wanted to know was not "how to test an ABS system", BUT rather "what are the Pros for paying extra for ABS?", and "the Cons for just using standard 4 wheel disk brakes"?
Hey Al, forgot to ask "what is a DRL"?
Pro: Braking max pressure per wheel, allows for more controlled stops. allows for an easier integration of traction control & stability control systems. Maintains steering control under adverse conditions with maximum braking. prevents lockups and tire flat spotting, etc.
Con: More expensive to build, maintain, repair. Uses power, extra weight, difficult to diagnose without equipment. Under some stopping conditions lengthens stopping distance. Requires re-learning of how to emergency stop (easily done).
Biggest Con: cost Biggest Pro: control
hope this helps.
PS 4 wheel disk brakes are undertuilized 99% of the time which is why the rears often seize up. Drums aren't a bad option for the rears. Honestly.
DRL stands for Daytime Running Lights. On all new cars, the headlights automatically turn on using lower wattage than normal, until you turn the headlights on.
Sharky
Hey Guys, My Buick just threw codes C1216, C1221, & C1225 all pertaining to my ABS. As explained to me (novice), I now have to wait till the problem gets worse because it is an intermittent problem when hooked up at the dealer. This is the second place I've taken it to and it's $80.00 a pop for diagnostics. As I know some replacement costs are quite high, can't I just get the damned (sensors) things replaced? Also, after reading this post, Am I correct and believing that besides additional braking handling, I can live without the ABS working. Last time I needed them they actually the control issue worse (in the snow) as a controlled braking would have had a better result. Thanks for your time. BB
Hey Guys, My Buick just threw codes C1216, C1221, & C1225 all pertaining to my ABS. As explained to me (novice), I now have to wait till the problem gets worse because it is an intermittent problem when hooked up at the dealer. This is the second place I've taken it to and it's $80.00 a pop for diagnostics. As I know some replacement costs are quite high, can't I just get the damned (sensors) things replaced? Also, after reading this post, Am I correct and believing that besides additional braking handling, I can live without the ABS working. Last time I needed them they actually the control issue worse (in the snow) as a controlled braking would have had a better result. Thanks for your time. BB
Hey Guys, I just had my Century hooked up to the computer for the sceond time (1 @ dealer, 1 @ Good service shop) and it has been determined that codes C1216, C1221, & C1225 all pertaining to the ABS sensors are the culprit. My problem is this is an intermittent problem and am being told that I have to wait till it happens more regularly. At $80.00 a pop for diagnostics, can't I just get the damn things replaced? I know it is costly but I am not being given that option since they can't pinpoint the problem. They seem to think that two sensors may be causing the 3rd to fail but want it to be more regular. After reading this forum and topic, am I correct in believing that I can live without the ABS all together from a mechanical standpoint? I know these are designed for our safety, but they have caused 2 instanaces in snow that gave me a lack of control compared to controlled braking (the old fashioned way). I value any input I can get since I am only a novice. BB
Hey Guys, I just had my Century hooked up to the computer for the sceond time (1 @ dealer, 1 @ Good service shop) and it has been determined that codes C1216, C1221, & C1225 all pertaining to the ABS sensors are the culprit. My problem is this is an intermittent problem and am being told that I have to wait till it happens more regularly. At $80.00 a pop for diagnostics, can't I just get the damn things replaced? I know it is costly but I am not being given that option since they can't pinpoint the problem. They seem to think that two sensors may be causing the 3rd to fail but want it to be more regular. After reading this forum and topic, am I correct in believing that I can live without the ABS all together from a mechanical standpoint? I know these are designed for our safety, but they have caused 2 instanaces in snow that gave me a lack of control compared to controlled braking (the old fashioned way). I value any input I can get since I am only a novice. BB
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