6
z
Locate the vacuum hose joint for the intake
air and PCV systems.
z
Access the PCM and monitor the SHRTFT1
and SHRTFT2 PIDs.
z
Restrict the vacuum lines one at a time for 30
s. If a vacuum leak in the intake is present,
the SHRTFT PID values decrease as the hose
is restricted.
z
Is the decrease in the SHRTFT PIDs more
than 15% when one of the vacuum hoses is
restricted?
NOTE:
z
Restricting the EVAP vapor hose while the
EVAP emission canister is purging may
shift the SHRTFT. Perform a visual
inspection if necessary.
z
When monitoring for a decrease in the
SHRTFT PIDs in the following steps, if
SHRTFT1 15% and the hose is
restricted, SHRTFT1 decreases to-7%. The
total decrease in the SHRTFT PIDs equals
22%.
No
Inspect the intake air system for a vacuum
leak in the intake manifold or intake
gaskets. Repair if necessary. Then go to
the next step.
7
VACUUM LEAK REPAIR VERIFICATION
z
Access the PCM and monitor the SHRTFT1
and SHRTFT2 PIDs.
z
Allow the engine to stabilize at the
temperature necessary to recreate the
concern.
z
Record the SHRTFT1 and SHRTFT2 PID
values.
z
Turn the ignition switch off.
NOTE:
z
If the freeze frame ECT PID is available,
stabilize the engine at the temperature
recorded by the freeze frame ECT PID. If
the freeze frame ECT PID is not available,
maintain the engine coolant temperature
between 82-101°C {180-215°F} and the
intake air temperature less than 46°C {115°
F}.
Yes
Reset the keep alive memory. Then go to
Step 13.
2008 Mazda CX-9 Grand Touring
2008 ENGINE PERFORMANCE On-Board Diagnostic (MZI-3.7) - Mazda CX-9
Microsoft
Sunday, November 15, 2009 10:08:35 AM
Page 109
© 2005 Mitchell Repair Information Company, LLC.
