February 2007 Air Repair OBDII Review 33
2006 Infiniti all models have difficulty in setting
readiness in particular Catalyst and Evaporate. Refer
to the specific drive cycles from Infiniti for the specific
1996 & 1997 Jaguar – Difficult to set monitors
and sometimes run out of sequence. Once all other
recommended diagnostic strategies have been
exhausted. Replacing the PCM has been proven to be
the logical fix. An updated TSB is in process.
1999-2000 Jeep Grand Cherokee. Readiness
monitors will not set to ready with a generic scan tool.
Reprogram for the PCM is available.
2000 Jeep Grand Cherokee, Cherokee and Wrangler
unable to communicate with a generic scan tools or
with DRB-III in generic mode. Reprogram for PCM
2002 Land-Rover Freelander is missing pin #5 to
establish communication. A TSB is available which
splices a ground lead to pin #5 of the DLC.
1996-2004 Lamborghini all models. May experience
readiness monitor retention. A reprogram is available
at a Lamborghini dealership.
1996-1998 Mazda all models – Monitors are hard to
set. Contact Mazda for the specific drive trace for year
2000 Mazda MPV. Needs to be reflashed to establish
communication with generic scan tools. The following
Web site can be used to determine if the vehicle is
included in the reflash bulletin.
This reflash may also help vehicles that are not
included in the bulletin.
1996 -1997 Nissan all models – Monitors are difficult
to set. All Models NTB98-018c Drive Traces.
Common OBDII Known Manufacturer Issues and the
Fixes — 1996–2003 MY
Continued from page 32.
VEHICLE FAILED TO COMMUNICATE
WITH THE EMISSION TEST LANE
When a vehicle’s On Board Diagnostics system (OB-DII)
won’t communicate with the emissions test lane com-puter,
there are several things you may want to be checked
to ensure that the proper communication can take place.
The first thing to check for is power on pin #16. There
should be full system voltage with the vehicle running.
Next verify the ground. To check the ground circuit,
disable the vehicle so that it will not start. Do a volt drop
check on Pin #5 (which is the signal ground) to the battery
negative terminal with the engine cranking. This will give
you a good dynamic test. There should be less than 0.2
volts. Pin #5 may not be used on all vehicles. Check the
wiring diagram for conformation. If there is no Pin in posi-tion
#5 this may be the problem. The emissions lane uses
Pin #5 for ground.
There are two sides to an OBDII system, the manufac-turer/
vehicle specific side and the generic/global side. The
OBDII tests performed at the test station must communica-tion
and comply with the generic/global side.
If your scanner is not self-powered with its own in-ternal
battery, you may or may not be able to read the data
coming from the computer. Most scanners rely on power
and ground from the vehicle to operate. If your scanner is
self-powered, you will probably be able to read the data
coming from the vehicle and think that nothing is wrong.
For complete information about checking OBDII vehi-cles,
see the article in the July 2004 issue of AIR REPAIR
on page 9 available on the Web site at www.epa.state.il.us.
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