Clearing DTCS In Generic OBD II Mode Or With A Generic Scan Tool (ASN0305-11)

CLEARING DTCS IN GENERIC OBD II MODE OR WITH A GENERIC SCAN TOOL

ACURA SERVICE NEWS

SERVICE INFORMATION

Acura vehicles, like all vehicles certified for sale in the U.S. since 1996, must comply with a common data communication protocol known as On-Board Diagnostics II (OBD II). Vehicle manufacturers can have their own communication system as long as they comply with the OBD II requirements.

American Honda has supplied two different scan tools to Acura dealerships. The first to come out was the PGM Tester. It services all 92-03 Acura vehicles but it's no longer supported by American Honda. The latest evolution is the Honda Diagnostic System (HDS). It's the PGM Tester's replacement and it services all current Acura models as well as the older ones. The HDS, like the earlier PGM Tester, features a Generic OBD II mode. In this mode, the HDS works the same as any aftermarket scan tool. A Generic OBD II scan tool must be able to display DTCs and to clear them.

If you try to clear DTCs on an Acura vehicle using the HDS or PGM Tester in Generic OBD II mode or a generic scan tool, you might not get the results youd expect. Thats because Acura vehicles actually use three different kinds of clear commands: DTC CLEAR, ECM/PCM RESET, and more recently, CKP PATTERN CLEAR. If youre using the HDS or PGM Tester in Honda System mode, the level of clearance varies. If youre using the HDS or PGM Tester in Generic OBD II mode or a generic scan tool, there's just one clear command. It clears all  learned values.

	DTC	Freeze Data	Readiness Codes	Idle Learn Data	CKP Pattern Data (V6 Models)
HDS or PGM Tester in Honda System Mode
DTC CLEAR	X	X	X
ECM/PCM RESET	X	X	X	X
CKP PATTERN CLEAR*					X
HDS or PGM Tester in Generic OBD II Mode; Generic Scan Tool
CLEAR	X	X	X	X	X

*This command is available only on the HDS.

Since all the learned values are cleared in Generic OBD II mode or with a generic scan tool, don't forget to do the idle learn procedure. And if you're working on a V6 model, don't forget to do the CKP pattern learn procedure, or you could wind up with a misfire DTC when theres really no problem. Refer to the appropriate S/M or ISIS for idle learn and CKP pattern learn procedures.