Mazda CX-9 Grand Touring 2009 Manual page 945

2008 ENGINE PERFORMANCE On-Board Diagnostic (MZI-3.7) - Mazda CX-9
Are there any malfunction?
VERIFY TROUBLESHOOTING OF
DTC P0123 HAS BEEN COMPLETED
Make sure to reconnect all
disconnected connectors.
Clear the DTC from the PCM memory
8
using the M-MDS.
Start the engine.
Perform the "KOEO/KOER self-test".
(See KOEO/KOER SELF TEST
[MZI-3.7].)
Is same DTC present?
VERIFY AFTER REPAIR PROCEDURE
Perform the "AFTER REPAIR
9
PROCEDURE". (See AFTER
REPAIR PROCEDURE [MZI-3.7].)
Are any DTCs present?
DTC P0128 [MZI-3.7]
DTC P0128 (MZI-3.7) DETECTION CONDITIONS AND POSSIBLE CAUSES
DTC P0128 Coolant thermostat (coolant temp below thermostat regulating temperature)
DETECTION
CONDITION
POSSIBLE CAUSE
DIAGNOSTIC PROCEDURE
DTC P0128 (MZI-3.7) DIAGNOSTIC PROCEDURE
STEP
VERIFY FREEZE FRAME DATA HAS BEEN
RECORDED
1
Has FREEZE FRAME DATA been
recorded?
VERIFY RELATED REPAIR INFORMATION
2008 Mazda CX-9 Grand Touring
P0128 Indicates that the thermostat monitor has not achieved the required
engine operating temperature within a specified amount of time after starting
the engine.
Insufficient warm up time
Low engine coolant level
Leaking or stuck open thermostat
Inoperative cylinder head temperature (CHT) sensor
INSPECTION
No Go to the next step.
Replace the PCM, then go to the next step. (See
Yes PCM REMOVAL/INSTALLATION [MZI-
3.7] .)
No Go to the next step.
Go to the applicable DTC inspection. (See DTC
Yes
TABLE [MZI-3.7].)
No Troubleshooting completed.
Yes Go to the next step.
Record FREEZE FRAME DATA on the
No
repair order, then go to the next step.
Perform repair or diagnosis according to
ACTION