CEL Guidance
11-21-2007, 07:17 AM
#21
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Yeah, hindsight is a wonderful thing. Unfortunately I really need the car to drive at the moment and didn't really want to drive it around without knowing what the CEL was for - hence going straight to the dealers. Lesson learnt, I might just pick up a code reader anyway for next time.
11-21-2007, 08:07 AM
#23
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Thanks Bibbs, I'm going to let the dealer finish looking given that they've done half a job so far and I want to push for some good will work, but if they don't have any good suggestions or want more money for guesswork I may well take you up on your offer!
11-21-2007, 09:24 AM
#24
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have i missed a line in this thread? havent read anyone ask or state if the S drives ok?
does it pull ok (engine under load), or is there an obvious misfire, does vtec kick in, any lack of power etc? does the engine sound tappy?
i had mine drive perfect apart from vtec engagement - turned out to be a worn lobe on the camshaft. cam follower became damaged/faulty and then caused the cam lobe to wear. ended up with a cam & follower at a rather high cost.
p0399 is a 'not yet fully diagnosed' misfire. ecu detects a misfire but not had enough misfires to diagnose which cylinder.
honda ECU's require two drive cycles with the fault active for it to store a code. the first drive cycle is a temorary store which is deleted when ignition is turned off (but keeps to one side in the ecu memory, no CEL light). if on that second subsequent drive cycle the same fault appears, it stores a permanent fault.
depending what symptoms you have will obviously determine where the fault lies.
edit: i dont know how good you are on mechanics/electronics, but just because the code reader says it's a misfire, doesnt mean it's an actual misfire - read it more like 'reduction in cylinder performance' - headgasket, compression, sparkplugs, cam, injectors etc.
does it pull ok (engine under load), or is there an obvious misfire, does vtec kick in, any lack of power etc? does the engine sound tappy?
i had mine drive perfect apart from vtec engagement - turned out to be a worn lobe on the camshaft. cam follower became damaged/faulty and then caused the cam lobe to wear. ended up with a cam & follower at a rather high cost.
p0399 is a 'not yet fully diagnosed' misfire. ecu detects a misfire but not had enough misfires to diagnose which cylinder.
honda ECU's require two drive cycles with the fault active for it to store a code. the first drive cycle is a temorary store which is deleted when ignition is turned off (but keeps to one side in the ecu memory, no CEL light). if on that second subsequent drive cycle the same fault appears, it stores a permanent fault.
depending what symptoms you have will obviously determine where the fault lies.
edit: i dont know how good you are on mechanics/electronics, but just because the code reader says it's a misfire, doesnt mean it's an actual misfire - read it more like 'reduction in cylinder performance' - headgasket, compression, sparkplugs, cam, injectors etc.
11-21-2007, 09:51 AM
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I'm afraid some of you guys are being a little simplistic about how easy diagnostics are. As stated above, the codes related to a misfire and the plugs were due within a few K anyway so they are a natural place to start. On a car that was seemingly running mostly ok would you rather they started by chasing an engine fault at
11-21-2007, 11:17 PM
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It doesn't sound harsh but if you are into diagnostics you must know that the answers don't always just pop up on a computer screen 
.
They had a misfire reported but you wouldn't necessarily see a definite fault with a plug when visually inspecting it - the only way of proving them to be faulty (or not) is to replace them, plus they are out now anyway and due for change soon so they are saving on future labour costs for the customer by doing them now.
Replacing parts can get expensive but there are three options here -
1) Spend a reasonable but not excessive time looking for the most likely solution based on the available evidence. If more than one possibility presents itself, consider the likelihood of a fix against the cost of repair and make a decision on how to proceed. You may or may not fix the car on first attempt but you are minimising the labour costs, which may otherwise greatly exceed the cost of parts, and you are progressing the job toward a fix.
2) Do the initial diagnosis and if it doesn't lead to a cast iron conclusion within a reasonable time hand the car back to the customer with a bill for the labour so far and explain that the problem would need to progress and get worse before an accurate diagnosis can be made. This is honest and fair but risks ongoing damage to components on the car and the customer may well feel that he has been charged for absolutely no result or progress.
3) Continue on a labour only basis until the fault can be conclusively diagnosed. This may seem like the ideal solution but if the number of hours spent on the vehicle massively outstrips the cost of a repair that was always a likely possibility then the customer ends up with an inflated bill that he did not need. Additionally, some problems reach a stage where the only way to see if an actual or possible fault is causing the reported symptom is to fit the part and monitor the result.
Option 1 is the way to go. So long as it is fully and honestly explained to the customer (something that may not have happened in this case
) it is the fairest and most effective way of finding a problem.
. They had a misfire reported but you wouldn't necessarily see a definite fault with a plug when visually inspecting it - the only way of proving them to be faulty (or not) is to replace them, plus they are out now anyway and due for change soon so they are saving on future labour costs for the customer by doing them now.
Replacing parts can get expensive but there are three options here -
1) Spend a reasonable but not excessive time looking for the most likely solution based on the available evidence. If more than one possibility presents itself, consider the likelihood of a fix against the cost of repair and make a decision on how to proceed. You may or may not fix the car on first attempt but you are minimising the labour costs, which may otherwise greatly exceed the cost of parts, and you are progressing the job toward a fix.
2) Do the initial diagnosis and if it doesn't lead to a cast iron conclusion within a reasonable time hand the car back to the customer with a bill for the labour so far and explain that the problem would need to progress and get worse before an accurate diagnosis can be made. This is honest and fair but risks ongoing damage to components on the car and the customer may well feel that he has been charged for absolutely no result or progress.
3) Continue on a labour only basis until the fault can be conclusively diagnosed. This may seem like the ideal solution but if the number of hours spent on the vehicle massively outstrips the cost of a repair that was always a likely possibility then the customer ends up with an inflated bill that he did not need. Additionally, some problems reach a stage where the only way to see if an actual or possible fault is causing the reported symptom is to fit the part and monitor the result.
Option 1 is the way to go. So long as it is fully and honestly explained to the customer (something that may not have happened in this case
) it is the fairest and most effective way of finding a problem.
11-22-2007, 12:08 AM
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Originally Posted by t11ner,Nov 22 2007, 08:17 AM
1) Spend a reasonable but not excessive time looking for the most likely solution based on the available evidence. If more than one possibility presents itself, consider the likelihood of a fix against the cost of repair and make a decision on how to proceed. You may or may not fix the car on first attempt but you are minimising the labour costs, which may otherwise greatly exceed the cost of parts, and you are progressing the job toward a fix.
Option 1 is the way to go. So long as it is fully and honestly explained to the customer (something that may not have happened in this case ) it is the fairest and most effective way of finding a problem.
Option 1 is the way to go. So long as it is fully and honestly explained to the customer (something that may not have happened in this case
) it is the fairest and most effective way of finding a problem.
Thanks everyone for your comments and advice so far, these forums are fantastic!
11-22-2007, 12:25 AM
#29
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Im fully aware things dont just pop up on a computer, my ponit is that they have all the tools available and interpretation of OBD diagnostics is where someone really earns their corn.
Option 1 is not how it works in the real world unfortuantely, and that is also what im getting at.
Option 1 is not how it works in the real world unfortuantely, and that is also what im getting at.
11-22-2007, 12:37 AM
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Originally Posted by MB,Nov 22 2007, 09:25 AM
Option 1 is not how it works in the real world unfortuantely, and that is also what im getting at.
They will get the most junior kiddie to plug it in and follow notes in a manual.
They will charge you a lot for the "priviledge".
It's why forums such as this are great, as there is a LOT of knowlegable people on here. It's free, and if you have a basic tool kit and don't mind getting dirty, you can do it yourself.
