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Speedo is calibrated in the firmware. I don’t suppose it looks like it’s showing km/h instead of mph? 1 km = 0.62 miles. Not quite double, but pretty close.

Maybe they flashed it with the wrong image. :/ but, Summit is typically pretty reliable and competent.

Weird.


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Curious: what does your scan tool say the speedometer should be displaying? Does it match what the dash gauge is showing?


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Discussion Starter #123
All indications are MPH, I did see where it was listed as manual transmission but I changed that.

Fuse 33 looks good and scan tool shows start relay opening and closing. the one constant is the O2 sensor heaters, I checked both sensors for open across the heater element and both appear to be good.

Off to the dealer or a 2:00
 

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Discussion Starter #124
Back from the dealer, a reflash is all that was needed.

Apparently, the info that the ECM had was pretty much all wrong so that's why my speedo was reading over 4 times faster than I was actually going.

Happiness is ....
 

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Hooray! Success!

I'd call Summit and just let them know, and mention how much it cost to fix their mistake. Not rudely, but... if it was my shop, I would want to know. They have a really strong reputation. I'm not sure if they'd do anything for you, but it's worth mentioning to them in either case.

Fingers crossed that the fix remains... fixed.

On the up side: $185 is a good price for an ECM. WAY better than what the dealership would charge.
 

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Discussion Starter #127 (Edited)
Curious: what does your scan tool say the speedometer should be displaying? Does it match what the dash gauge is showing?


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Scan tool indicated the same thing, about 111mph (actually about 26 mph) when the engine would stumble and RPM drop back to about 1000, and the VSS said the same thing.
 

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Weird. An incorrect tune can cause all kinds of issues. The CPU in the ECM has a ton of output pins (and additional circuitry) that ultimately teminate in the big harness connectors. Software determines what the signals on those pins mean - but its intepretation has to agree with the physical implementation (aka, the crap that's actually in the car). One tune can say pin 158 is a speed sensor, while another version may expect that the same pin is an analog coolant temp sensor input. Then, there's manual vs automatic. The firmware revision for the manual may expect a certain pin to be a clutch sensor input, while the one for the automatic might expect the same one to be a Park sensor (or a key-in-ignition signal, or a dome light (ha) on, or whatever). The same physical ECM model can be used for many completely-incompatible vehicles. V8s, 4-bangers, Diesels, 4wd, FWD, RWD, manual, auto, etc.

I love the flexibility that programmable processors provide. There are things we can do now (or 15 years ago) that would otherwise be impossible. But, firmware is a PITA to debug without the proper tools. And the OEMs never provide the proper tools. Give me an ssh server on my car and root access, and we'll have a party. What we have now is slightly better than throwing darts.

/rant

Everything is working now, correct?
 

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Back from the dealer, a reflash is all that was needed.

Apparently, the info that the ECM had was pretty much all wrong so that's why my speedo was reading over 4 times faster than I was actually going.

Happiness is ....
Congratulations! Glad you finally got it sorted out.
Weird. An incorrect tune can cause all kinds of issues. The CPU in the ECM has a ton of output pins (and additional circuitry) that ultimately teminate in the big harness connectors. Software determines what the signals on those pins mean - but its intepretation has to agree with the physical implementation (aka, the crap that's actually in the car). One tune can say pin 158 is a speed sensor, while another version may expect that the same pin is an analog coolant temp sensor input. Then, there's manual vs automatic. The firmware revision for the manual may expect a certain pin to be a clutch sensor input, while the one for the automatic might expect the same one to be a Park sensor (or a key-in-ignition signal, or a dome light (ha) on, or whatever). The same physical ECM model can be used for many completely-incompatible vehicles. V8s, 4-bangers, Diesels, 4wd, FWD, RWD, manual, auto, etc.

I love the flexibility that programmable processors provide. There are things we can do now (or 15 years ago) that would otherwise be impossible. But, firmware is a PITA to debug without the proper tools. And the OEMs never provide the proper tools. Give me an ssh server on my car and root access, and we'll have a party. What we have now is slightly better than throwing darts.

/rant

Everything is working now, correct?
The speed problem is probably not a mis-identified input, but rather an incorrect sensor resolution setting. If the ECM is told to look at a 100 pulse-per-revolution sensor but the car actually has a 400 pulse-per-revolution sensor, the speed indication is going to follow vehicle speed but will be four times larger than it should be.
 

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Yeah - I get that. My point was that an incorrect image can create a lot more problems than merely a poorly-running car. With the proper specs and a JTAG (hey. we're talking 2009 here) interface, I could make that thing into a very inefficient Bitcoin node.

Horrible Startup Idea #42: put an RF power / data gadget in every junk car in every junkyard in the US and rent out the processor time.

Many of the PWM inputs have a scale & offset. There's certainly one for the speedo which is typically used to adjust for tire diameter. If that's at some crazy default value that makes no sense in the real world, hilarity will ensue. If other parts of the code really believe that you're doing 111mph in 1st gear, new and entertaining failure modes or error conditions may present.
 

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Discussion Starter #131 (Edited)
raygun - Yes everything seems good. I only wish I could have taken the tech aside to see if he could have taken care of that damn throttle delay.

Is anyone interested in the old ECM to play with?

Thank you all again.
 

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Discussion Starter #133
I believe it is referred to as Torque management.
 

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What throttle delay?
dosent your have throttle delay??? musta been tuned out.....I hate it.I think the tq management is a different opp. I gotta get mine tuned out...gotta do a lot of stuff...gotta lota stuff to do, not only on my car.thus the car just gets driven not updates.:frown2:
 

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dosent your have throttle delay??? musta been tuned out.....I hate it.I think the tq management is a different opp. I gotta get mine tuned out...gotta do a lot of stuff...gotta lota stuff to do, not only on my car.thus the car just gets driven not updates.:frown2:
No, my cars do not have any throttle delay. I depress the pedal and the engine reacts. The RL reacts slightly slower albeit with a lot more authority than the NA, but they both react promptly.
 

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Discussion Starter #136
JohnWR -
No, my cars do not have any throttle delay. I depress the pedal and the engine reacts. The RL reacts slightly slower albeit with a lot more authority than the NA, but they both react promptly.
The effect I refer to is a delay that I experience when I want or need to accelerate quickly from either a standstill or rolling along. I see the need to move NOW, hit the gas and wait for the engine to respond or the transmission to downshift.

Ok maybe it's milliseconds but it seems like an eternity, I'm old school ... carburetors, distributors with points, gas pedals with linkage, etc.

Maybe I have misunderstood but I am under the assumption that can be tuned out and maybe that's just the way it is with these cars and I just have to get used to it.
 

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Turbo lag, maybe?

With an automatic, there are a number of software parameters that affect latency.


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Discussion Starter #138
NA, Automatic. Wish it was turbo.
 

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JohnWR -

The effect I refer to is a delay that I experience when I want or need to accelerate quickly from either a standstill or rolling along. I see the need to move NOW, hit the gas and wait for the engine to respond or the transmission to downshift.

Ok maybe it's milliseconds but it seems like an eternity, I'm old school ... carburetors, distributors with points, gas pedals with linkage, etc.

Maybe I have misunderstood but I am under the assumption that can be tuned out and maybe that's just the way it is with these cars and I just have to get used to it.
It could just be the automatic transmission. I haven't driven one, but that sounds like typical torque converter behavior.
 
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