Diagnostic procedure

WARNING: This page is about a different car, the 2009 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

STEP	INSPECTION	RESULTS	ACTION
1	Connect the M-MDS to the DLC-2. Access ECT PID. Verify ECT PID is less than 116°C {241°F} during driving. Is ECT PID less than specification?	Yes	Go to the next step.
1		No	Inspect CHT sensor. If CHT sensor is normal, inspect the cooling system for cause of overheating.
2	Connect the M-MDS to the DLC-2. Access IAT and MAF PIDs. Monitor each PID. (See PCM INSPECTION [MZI-3.7] .) Are PIDs normal?	Yes	Go to the next step.
2		No	IAT PID: Inspect IAT sensor MAF PID Inspect MAF sensor
3	Connect the M-MDS to the DLC-2. Switch ignition to ON (engine off). Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [MZI-3.7] .)
3		No	No DTC is displayed: Go to the next step.
4	Is engine compression correct?	Yes	Go to the next step.
4	Is engine compression correct?	No	Inspect for cause.
5	Install fuel pressure gauge between fuel pipe and fuel distributor Start the engine and idle it Measure fuel line pressure during idle Is fuel line pressure correct during idle? (See FUEL LINE PRESSURE INSPECTION [MZI-3.7] .)	Yes	Go to the next step.
5		No	Low: Perform "Fuel Pump Operation Inspection" and "Fuel Pump Control System Operation Inspection", repair or replace according to inspection results. Inspect the fuel line for clogging. If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZI-3.7] .) High: Perform "Fuel Pump Operation Inspection" and "Fuel Pump Control System Operation Inspection", repair or replace according to inspection results. If there is no malfunction, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZI-3.7] .)
6	Inspect the knock sensor Is the knock sensor normal?	Yes	Inspect ignition timing.
6	Inspect the knock sensor Is the knock sensor normal?	No	Replace the knock sensor.
7	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 Information and perform repair or diagnosis If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.