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mattmag

join:2000-04-09
NW Illinois

mattmag to fartness

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Re: Resetting ECM-ECU on old car - helpful?

said by fartness:

It can change if the car is driven differently. If grandma drives slow and then gives the car to someone who is lead footed, the transmission for instance, might be set to grandma's tone, and not a lead foot.

Not so much the transmission really, but more so the fuel delivery curve. For the most part, ECM parameters are about engine emissions and settings that effect them rather than felt performance.
theboz1419
join:2003-02-12
Puyallup, WA

theboz1419

Member

I know my car is newer, 2006 Honda civic Ex, but resetting has helped solve a shifting problem i had when shifting into 2nd and 3rd.

After I bought the car 8 months ago it started to have a problem of losing power when I shifted into 2nd and sometimes 3rd. The car would hesitate and jerk for a second and then it would resume accelerating normally. My mechanic thought it was maybe my clutch slipping or I thought maybe the trans was the problem,

A few weeks ago my cars battery died and after replacing the battery, the car is shifting like it should and is not hesitating and seems like it has more power then before.

So it has helped in my case. But I think it would not help much on a older car.

MooJohn
join:2005-12-18
Milledgeville, GA

MooJohn

Member

If it had anything to do with adaptive parameters, it will "adapt" its way back to where it was in time.

The computer never quits adjusting. Changes in one direction may be slower than the other when it comes to safety. For example, timing is removed in big chunks when knock is detected and it is added back very slowly. A reset after a bad tank of gas my speed this but the car will eventually reach the same state whether or not it is reset.

Doctor Olds
I Need A Remedy For What's Ailing Me.
Premium Member
join:2001-04-19
1970 442 W30

Doctor Olds to theboz1419

Premium Member

to theboz1419
said by theboz1419:

I but resetting has helped solve a shifting problem i had when shifting into 2nd and 3rd.

After I bought the car 8 months ago it started to have a problem of losing power when I shifted into 2nd and sometimes 3rd. The car would hesitate and jerk for a second and then it would resume accelerating normally. My mechanic thought it was maybe my clutch slipping or I thought maybe the trans was the problem,

A few weeks ago my cars battery died and after replacing the battery, the car is shifting like it should and is not hesitating and seems like it has more power then before.

So it has helped in my case.

Weak battery was the cause of your issues, not resetting anything.

shdesigns
Powered By Infinite Improbabilty Drive
Premium Member
join:2000-12-01
Stone Mountain, GA

shdesigns

Premium Member

said by Doctor Olds:

Weak battery was the cause of your issues, not resetting anything.

+1

Jim Gurd
Premium Member
join:2000-07-08
Livonia, MI

Jim Gurd to Doctor Olds

Premium Member

to Doctor Olds
said by Doctor Olds:

Weak battery was the cause of your issues, not resetting anything.

Not sure I understand this. How does a weak battery affect how a transmission shifts? Once the engine is running, the alternator is powering the electrical system in the vehicle.
theboz1419
join:2003-02-12
Puyallup, WA

theboz1419

Member

Yeah, im wondering too, how a weak battery would cause shifting issues while accellerating. All a battery is used for is to start the car. After the car is on the altenator takes over and the battery becomes a drain until its charged again.

In fact when I took my car in to get a new battery, the old 7 year old battery still was able to get a good reading on a battery tester, and was around 13.5 volts.

I had the accel. problem for 6+ months and since I had the battery replaced 3 weeks ago, no more accel. problems. The battery would not cause issues other then not starting the car or causing the car to stall while in idle if the battery was totally gone. The Alternator either works or it does not.

Juggernaut
Irreverent or irrelevant?
Premium Member
join:2006-09-05
Kelowna, BC

Juggernaut

Premium Member

said by theboz1419:

All a battery is used for is to start the car.

That's incorrect. A battery is also a power buffer, and used to supply a stable voltage, and current. Alternators fluctuate as demand from the battery is needed, or exceeded.

Doctor Olds
I Need A Remedy For What's Ailing Me.
Premium Member
join:2001-04-19
1970 442 W30

Doctor Olds to theboz1419

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to theboz1419
said by theboz1419:

In fact when I took my car in to get a new battery, the old 7 year old battery still was able to get a good reading on a battery tester, and was around 13.5 volts.

No 12V Automotive starting battery is 13.5 volts. That is the alternator output, not the battery. A 12 volt battery that is new or in good condition is 12.6 volts (2.1 volts per cell) when fully charged.



Vchat20
Landing is the REAL challenge
Premium Member
join:2003-09-16
Columbus, OH

Vchat20 to Juggernaut

Premium Member

to Juggernaut
said by Juggernaut:

said by theboz1419:

All a battery is used for is to start the car.

That's incorrect. A battery is also a power buffer, and used to supply a stable voltage, and current. Alternators fluctuate as demand from the battery is needed, or exceeded.

This. And with pretty much all cars since around ~2000 or so having a lot of engine functions electronically controlled, a weak battery and forcing these systems to rely more on the alternator can cause all kinds of issues. And for most vehicles if they sense a low battery voltage, they will adjust the alternator output accordingly to try and recover which can also exacerbate things.

As a personal anecdote, my mom's prior vehicle, a 2000 Durango, had some strange issues at one point especially concerning staying running after starting. It would crank and start fine with no struggle but after a second or so would outright die unless you kept the revs up and even then it would struggle some. Mind you this was with the 4.7L engine which was the first in the model to go to a distributorless ignition (ie: Coil-on-pack, driven directly by the ECU). Long story made short it was narrowed down to a combination of a weak battery and battery clamps deteriorated greatly (possibly causing the weak battery issue). After the clamps and battery were replaced, the problems completely vanished from that point forward.