[redracer]

Will disconnecting the 12V negative cable reset the OBD/DTC codes, and if not how can they be cleared?
A mechanic told me that while disconnecting the 12V may turn out the IMA/CEL lights it will not clear the codes. He tried resetting the above codes with a scan tool but could not.
I want to make sure the 1447 was not caused by something other than a bad IMA battery and made the following changes.

Initially my 2000 M/T had a IMA light on with a P1447 code, continued driving and then also got a P1449. After not driving for only a few days the 12V battery had to be jumped so the IMA light reset. After a few miles I got the check engine light, followed by the IMA light. The 12V (Honda battery) was bad after only a year and I found a totally severed/unattached ground strap. The dealer replaced my 12V and checked out the IMA battery, and replaced the ground strap but did not reset the codes. SOC went to 1 bar after little assist right away, IMA and CEL again. Codes show a P1445 in addition to 1447/1449 and the SOC remains at 1 bar always now.

Could the P1445 ("bypass contactor") or 1 bar SOC be caused if the dealer disconnected my BCM?? Even with the IMA and CEL lights on, the SOC showed fully charged. Not sure what the dealer did.

 

[Eli]

Disconnecting the 12V battery will completely clear all of the computer's memory; the ECM, MCM and BCM. There will be no more codes, you'll be starting fresh. A regular scan tool cannot reset IMA codes.

P1447 followed by P1449 is generally how the failure sequence goes.

The P1445 is the odd ball, it has nothing to do with the battery.

You would have many more codes than just a P1445 if anything were disconnected.

 

[sam]

So how do you reset the IMA codes?

 

[Willie Williford]

Disconnect the 12V battery for at least 15 sec.

Willie