How do I reset the PCM?

Tiny
JORGE76
  • MEMBER
  • 2007 HONDA ACCORD
  • 2.4L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 112,000 MILES
How to reset the ecm/pcm on accord 2007 without hds and how do the idle relearn. I not have problems just I need do the idle relearn but I need reset the ecm without the hds scanner
Friday, October 31st, 2014 AT 7:39 PM

9 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 42,833 POSTS
You can do a hard relearn of the system by removing the negative battery cable and holding it to the positive terminal. This will discharge the capacitors in the ECM and make the computer start from scratch. This video will help as well

https://youtu.be/ahK_eucFi-k

Clearly the video says that OBD I requires a battery disconnect but OBD II needs a scan tool. However, doing a battery disconnect for 10 minutes on OBD II will clear any stored DTC as it erases the active memory.

Here is a more specific guide.

https://www.2carpros.com/trouble_codes/obd2

https://www.2carpros.com/articles/check-engine-light-clear-codes

Please let us know if you need anything else to get the problem fixed.
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Thursday, August 31st, 2017 AT 5:39 PM
Tiny
MLAMPA
  • MEMBER
  • 22 POSTS
  • 2006 HONDA ACCORD
  • 80,400 MILES
I had taken my car in recently to get a recall fix for the secondary shaft bearing recall on my model of car. During this time, I was also experiencing some wierd issues with the vehicle. Stiff steering wheel, hard brake pedal, hard gas pedal, and acceleration hesitance all at the same time. Since then, it's been to a mechanic who had unplugged/plugged back in each and every connector on the car, and that fixed the wierd issues I was having, but I am still experiencing the acceleration/shifting hesitance.

I had also unplugged my MAF sensor and drove it around the block. It caused the CEL to go on. This I parked the car, plugged the sensor back in, started the car, and heard a slight clunk coming from what sounded like the intake manifold, like the sound of a butterfly plate retracting. My car hasn't driven the same way since I did this.

I am also hearing a "hissing" sound coming from the engine compartment when the card is idle and when I'm driving and accelerating.

I'm hoping that properly resetting ECU will help this matter out somewhat. Can you provide me with the proper steps to take to reset the ECU on my car? I would greatly appreciate it.
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Tuesday, May 11th, 2021 AT 6:45 PM (Merged)
Tiny
MHPAUTOS
  • MECHANIC
  • 31,938 POSTS
I forgot to add, the check light will have to be cleared with a scanner and then driven and re scanned to ensure all codes are cleared as well. this video well help.

https://youtu.be/ahK_eucFi-k

let me know.
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Tuesday, May 11th, 2021 AT 6:45 PM (Merged)
Tiny
MLAMPA
  • MEMBER
  • 22 POSTS
I've already had the check engine light turned off and scanned for any other codes. All is fine. I just still hear the hissing noise.

Wouldn't everything I'm experiencing be due to not having enough vaccuum?
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Tuesday, May 11th, 2021 AT 6:45 PM (Merged)
Tiny
MHPAUTOS
  • MECHANIC
  • 31,938 POSTS
You gotta check for that vacuum leak, a hissing will be a vacuum leak you must find this first.
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Tuesday, May 11th, 2021 AT 6:45 PM (Merged)
Tiny
MLAMPA
  • MEMBER
  • 22 POSTS
Hi there. Sorry it took me so long to reply. OK, so I took my car back to the mechanic to have him check for a vacuum leak. What he thought might have been it really wasn't because he had never removed it, but based on my telling him what I was hearing, he figured it was some hose to the intake manifold, but it wasn't.

What I am hearing now is noticeable but faint whining/whizzing sound coming from the engine compartment. I know it's normal for my car to whine or whiz a little a bit upon acceleration, but this starts as soon as I start the car and is consistant.

As I'm driving the car, I have been feeling like the transmission holds it's gear too long, like it doesn't want to shift to the next gear. It's almost like the engine and transmission are not communicating with each other in order to down shift and upshift at certain speeds and/or rpm. At the same time, I feel a tight gas pedal and a tight break pedal (there is hardly any play in the break pedal at all). I know the gas pedal is controlled by a "drive-by-wire" system and it shouldn't be affected by what I am feeling at all, but get this. When I pump the gas pedal repeatedly in park, and then put the car in drive and step on the gas, the gas pedal feels lighter and more responsive. But, as I drive the car, the pedals will go back to feeling tight again after just a few minutes worth of driving.

In addition to the above, I am experiencing the gear change and shifting issues. From a dead stop (1st gear), I accelerate and gain speed and can hear and feel the car shift into 2nd gear, and then to 3rd gear. But, by the time I reach 4th gear the RPM drops to 2000rpm and the car feels as if its struggling to accelerate past that. Then from 4th to 5th, I cannot hear nor feel the car go into that transition. And when I take my foot of the gas pedal, the rpm drops to about 950rpm and then rises back to between 1000 and 1200 rpm. Is this a transmission problem? Or, can it still maybe be a vacuum problem that affects the way the engine sends a signal to the transmission to shift or slow down? I've been having this issue for 4 months now, and nobody can seem to figure this one out. Oh, by the way, I had a firmware flash that was supposed to be proactive to save the secondary shaft bearing on the tranny to go out if if you shift from D to R over and over again to get out of snow, if you live in an area where you would need to do this.
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Tuesday, May 11th, 2021 AT 6:45 PM (Merged)
Tiny
KHLOW2008
  • MECHANIC
  • 41,815 POSTS
The problem seems to be from the Accelerator pedal. Any problem with it would cause the transmission shifting to be erratic. If no trouble codes are present, plug in a scan tool to monitor thr accelerator pedal sensor operations and go for a test drive. Note if the readings are within specs. Sometimes trouble codes do not show when a problem occurs as the readings are within specs but they could be on the outer edge whereby the PCM is not detecting any problem but performance is affected.
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Tuesday, May 11th, 2021 AT 6:45 PM (Merged)
Tiny
PRAKASH_G
  • MEMBER
  • 3 POSTS
  • 2003 HONDA ACCORD
  • 149,000 MILES
Hi I know that we can reset check engine light through fuse box but I m not sure which one should I remove and put back for reseting. I have attached the picture of fuse box so that you could help me figure out which one is reset.
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Tuesday, May 11th, 2021 AT 6:45 PM (Merged)
Tiny
CARADIODOC
  • MECHANIC
  • 33,727 POSTS
Mechanics just disconnect the negative battery cable for a minute.

Have you had the diagnostic fault codes read? Normally the goal is to avoid turning off the Check Engine light because that involves erasing any codes, then you lose that valuable information. The codes should be erased after the diagnosis and repairs are done.
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Tuesday, May 11th, 2021 AT 6:45 PM (Merged)

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