DTC P0171, P0174 [MZI-3.7]
DTC P0171, P0174 (MZI-3.7) DETECTION CONDITIONS AND POSSIBLE CAUSES
10
z
Disconnect the fuel supply line at the
fuel rail.
z
Disconnect the fuel supply line at the
fuel pump.
z
Check the fuel supply line for
restriction.
z
Apply 21-34 kPa {2142-3467 mmHg,
84.34-136.4 inHg} air pressure to the
fuel supply line.
z
Does air flow freely through the line?
NOTE:
z
Observe the Warnings, Cautions, and
Notes.
Yes
Replace the fuel pump module. Then go to the
next step.
No
Repair the cause of the restriction. Then go to
the next step.
11
VERIFY TROUBLESHOOTING OF DTC
P0148 HAS BEEN COMPLETED
z
Verify that all disconnected connectors
are reconnected.
z
Turn the ignition switch to the ON
position (Engine off).
z
Clear the DTC from the PCM memory
using the M-MDS.
z
Start the engine and run it at idle.
z
Retrieve DTCs using the M-MDS.
z
Is the PENDING CODE for this DTC
present?
Yes
Replace PCM, then go to the next step. (See
PCM REMOVAL/INSTALLATION [MZI-
3.7]
.)
No
Go to the next step.
12
VERIFY AFTER REPAIR PROCEDURE
z
Perform "AFTER REPAIR
PROCEDURE". (See
AFTER
REPAIR PROCEDURE [MZI-3.7]
.)
z
Are any DTC present?
Yes
Go to the applicable DTC inspection. (See
DTC TABLE [MZI-3.7]
.)
No
Troubleshooting completed.
DTC P0171
P0171: System too lean (RH)
DTC P0174
P0174: System too lean (LH)
DETECTION
z
P0171 indicates that the fuel/air ratio is too lean (RH).
z
P0174 indicates that the fuel/air ratio is too lean (LH).
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 105
© 2005 Mitchell Repair Information Company, LLC.
