Mazda CX-9 Grand Touring 2007 Manual page 922

2007 ENGINE PERFORMANCE Symptom Troubleshooting (MZI-3.5) - CX-9
1. Warm up the engine and idle it.
2. Connect the M-MDS to the DLC-2.
3. Select the RPM and FUELSYS1 PIDs.
4. Monitor the both PIDs while performing the following steps.
1. Depress the accelerator pedal and increase the RPM PID to 4,000 rpm .
2. Quickly release the accelerator pedal (brake pedal is not depressed) and verify that the FUELSYS1
PID is OL, and CL when the RPM PID drops below 1,200 rpm .
If not as specified, inspect the following.
If simulation function of the M-MDS is not used:
1. Warm up the engine and idle it.
2. Measure the fuel injector control signal wave profile using the oscilloscope while performing the
following steps.
1. Depress the accelerator pedal and increase the engine speed to 4,000 rpm .
2. Quickly release the accelerator pedal (brake pedal is not depressed) and verify that the wave profile
constant B+ , and appears wave, when the engine speed drops below 2,200 rpm .
If not as specified, inspect the following.
FUEL PUMP OPERATION INSPECTION
1. Remove the fuel-filler cap.
2. Turn the ignition switch to the ON position.
3. Turn the fuel pump relay from off to on using the FP PID and inspect if the operation sound is heard.
If no operation sounds is heard, proceed to next step.
2007 Mazda CX-9 Grand Touring
CHT sensor and related harness
(see CYLINDER HEAD TEMPERATURE (CHT) SENSOR INSPECTION
[MZI-3.5]. )
TR switch and related wiring harness
(see TRANSAXLE RANGE (TR) SWITCH INSPECTION [AW6A-EL, AW6AX-
EL]. )
CHT sensor and related harness
(see CYLINDER HEAD TEMPERATURE (CHT) SENSOR INSPECTION
[MZI-3.5]. )
TR switch and related wiring harness
(see TRANSAXLE RANGE (TR) SWITCH INSPECTION [AW6A-EL, AW6AX-
EL]. )