The purpose of this thread is to provide a detailed DIY procedure on how to disable the Variable Cylinder Management (VCM) system on 2008-2010 Honda Odyssey’s equipped with VCM engines. I will not discuss rationale or methodology used to arrive at the decision to disable the VCM system. Those discussions can be found in the thread labeled “VCM Long Term Reliabilty” on this site.
Perform this procedure with a cool engine and ignition switch OFF.
Photo's 1 and 2, from left to right, are illustrations of the "REAR" cylinder head. Disconnect the indicated (single wire) connector only. If you disconnect either or both of the remaining (two wire) connectors, the engine will only run in "LIMP HOME MODE". Limp home mode means it is running horribly.
Photo 3 is the "FRONT" cylinder head. Disconnect the indicated (single wire) connector only. If you disconnect the (two wire) connector, the engine will only run in "LIMP HOME MODE". Limp home mode means it is running horribly.
Seal both the connector and the connector cavity in the valve to prevent dirt from entering. Electrical tape is sufficient for this task. Secure the connector to the existing harness with a nylon zip tie.
Drive the vehicle at least 10 miles.
The CEL (Check Engine Light) MAY NOT illuminate immediately.
The ECO light may or may not come on during the test drive.
The CEL should come on the next time you start the vehicle if not sooner. Which means you have successfully disabled the VCM. You should never see the ECO light again unless you reverse this procedure.
Install black electrical tape over CEL on the instrument panel. Do not cover the Maintenance Minder lamp directly below it. It looks like a miniature wrench when illuminated.
Purchase a code scanner that is compatible with the Honda OBDII system. I found the Actron CP9575 is compatible.
Scan for codes. The scanner should read:
P3400 code for CYLINDER DEACTIVATION SYSTEM BANK 1 “PENDING”.
After a few drive cycles the same code remained activated and scanner added:
P3400 code for CYLINDER DEACTIVATION SYSTEM BANK 1 “CONFIRMED”.
The following week I scanned for codes and the scanner read in addition to the P3400 verbiage above:
P3497 code for CYLINDER DEACTIVATION SYSTEM BANK 2 “PENDING”.
P3497 code for CYLINDER DEACTIVATION SYSTEM BANK 2 “CONFIRMED”.
These codes are triggering the CEL illumination. It's the price you pay for no VCM.
If you are in a county that requires vehicle emissions testing, you simply plug the connectors back in. Clear the codes with your scanner. Drive cycle 100 miles, pass the test and disconnect again until next time.
Disclaimer: Anyone who disables VCM in a vehicle may or may not experience similar results and/or negative consequences. Anyone who disables the VCM on their vehicle, regardless of model year, accepts full financial responsibility for any negative consequences that may occur to the altered vehicle
Perform this procedure with a cool engine and ignition switch OFF.
Photo's 1 and 2, from left to right, are illustrations of the "REAR" cylinder head. Disconnect the indicated (single wire) connector only. If you disconnect either or both of the remaining (two wire) connectors, the engine will only run in "LIMP HOME MODE". Limp home mode means it is running horribly.
Photo 3 is the "FRONT" cylinder head. Disconnect the indicated (single wire) connector only. If you disconnect the (two wire) connector, the engine will only run in "LIMP HOME MODE". Limp home mode means it is running horribly.
Seal both the connector and the connector cavity in the valve to prevent dirt from entering. Electrical tape is sufficient for this task. Secure the connector to the existing harness with a nylon zip tie.
Drive the vehicle at least 10 miles.
The CEL (Check Engine Light) MAY NOT illuminate immediately.
The ECO light may or may not come on during the test drive.
The CEL should come on the next time you start the vehicle if not sooner. Which means you have successfully disabled the VCM. You should never see the ECO light again unless you reverse this procedure.
Install black electrical tape over CEL on the instrument panel. Do not cover the Maintenance Minder lamp directly below it. It looks like a miniature wrench when illuminated.
Purchase a code scanner that is compatible with the Honda OBDII system. I found the Actron CP9575 is compatible.
Scan for codes. The scanner should read:
P3400 code for CYLINDER DEACTIVATION SYSTEM BANK 1 “PENDING”.
After a few drive cycles the same code remained activated and scanner added:
P3400 code for CYLINDER DEACTIVATION SYSTEM BANK 1 “CONFIRMED”.
The following week I scanned for codes and the scanner read in addition to the P3400 verbiage above:
P3497 code for CYLINDER DEACTIVATION SYSTEM BANK 2 “PENDING”.
P3497 code for CYLINDER DEACTIVATION SYSTEM BANK 2 “CONFIRMED”.
These codes are triggering the CEL illumination. It's the price you pay for no VCM.
If you are in a county that requires vehicle emissions testing, you simply plug the connectors back in. Clear the codes with your scanner. Drive cycle 100 miles, pass the test and disconnect again until next time.
Disclaimer: Anyone who disables VCM in a vehicle may or may not experience similar results and/or negative consequences. Anyone who disables the VCM on their vehicle, regardless of model year, accepts full financial responsibility for any negative consequences that may occur to the altered vehicle