Mazda CX-9 Grand Touring 2009 Manual page 1347

18 Is the engine compression correct?
Verify test results.
If normal, return to diagnostic index to service any additional symptoms.
(See SYMPTOM DIAGNOSTIC INDEX [MZI-3.7].)
If malfunction remains, inspect related Service Bulletins and/or On-line Repair
19
Information and perform repair or diagnosis.
NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE [MZI-3.7]
NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE (MZI-3.7) DETECTION CONDITIONS
AND POSSIBLE CAUSES
12 LACK/LOSS OF POWER-ACCELERATION/CRUISE
DESCRIPTION Performance is poor under load (such as power down when climbing hills).
2008 Mazda CX-9 Grand Touring
2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9
If vehicle is repaired, troubleshooting completed.
If vehicle is not repaired or additional diagnostic information is not available,
replace the PCM.
(See PCM REMOVAL/INSTALLATION [MZI-3.7] .)
Improper A/C system operation
Erratic signal or no signal from CMP sensor
Air leakage from intake-air system parts
Restriction in intake-air system
Intake air temperature too hot
Improper operation of electronic throttle control system
Purge control solenoid malfunction
Brake dragging
Erratic signal from CKP sensor
Low engine compression
Vacuum leakage
Poor fuel quality
Erratic signal to ignition coil
Engine overheating
Inspect the following:
Valve timing
Yes
Internal transaxle part
Engine mounts
Check valve (two-way)
No Inspect for cause.