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Home >> Mazda >> 2007 >> 6 Mazdaspeed >> Repair and Diagnosis >> Engine Performance >> System >> Symptom Troubleshooting [Engine Control System L3 With TC) >> No. 13 Knocking/Pinging >> Diagnostic procedure
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Diagnostic procedure

DIAGNOSTIC PROCEDURE

STEP INSPECTION RESULTS ACTION
1 Connect the M-MDS to the DLC-2.
Access the ECT PID.
Verify that the ECT PID is less than 116°C {241°F} during driving.
Is ECT PID less than specified?
Yes Go to the next step.
No The cause of this concern could be from the cooling system overheating.
Perform the symptom troubleshooting "NO.17 COOLING SYSTEM CONCERNS - OVERHEATING."
(See NO. 17 COOLING SYSTEM CONCERNS-OVERHEATING ).
2 Inspect for the following:
  • Air leakage or restriction from intake-air system
  • Fuel quality (proper octane, contamination, winter/summer blend)
  • Exhaust system and/or three-way catalytic converter (TWC) restriction
  • Charge air cooler condition (restriction or damaged)

Are all items normal?
Yes Go to the next step.
No Service if necessary.
Repeat Step 2.
3 Perform the self-test function using the M-MDS.
Turn the ignition switch to the ON position.
Retrieve any DTCs.
Is a DTC displayed?
Yes DTC is displayed: 
Go to the appropriate DTC test.
(See DTC TABLE ).
No No DTC is displayed: 
Go to the next step.
4 Inspect the knock sensor.
(See KNOCK SENSOR (KS) INSPECTION ).
Is the knock sensor normal?
Yes Go to the next step.
No Replace the knock sensor.
(See KNOCK SENSOR (KS) REMOVAL/INSTALLATION ).
5 Perform the EGR system operation inspection.
(See EGR CONTROL SYSTEM INSPECTION ).
Does the EGR system operate properly?
Yes Go to the next step.
No Inspect or replace the malfunctioning parts, according to the inspection results.
6 Perform the TP sweep inspection.
(See THROTTLE POSITION (TP) SWEEP INSPECTION ).
Does the electronic throttle control system work properly?
Yes Visually inspect the throttle body (damaged/scratching). If normal, go to the next step.
No Inspect or replace the malfunctioning parts, according to the inspection results.
7 Perform the Variable Swirl Control System Operation Inspection.
(See VARIABLE SWIRL SYSTEM OPERATION INSPECTION ).
Does the variable swirl system work properly?
Yes Go to the next step.
No Inspect or replace the malfunctioning parts, according to the inspection results.
8 Perform the Wastegate Control System Operation Inspection.
(See WASTEGATE CONTROL SYSTEM OPERATION INSPECTION ).
Does the variable swirl system work properly?
Yes Go to the next step.
No Inspect or replace the malfunctioning parts, according to the inspection results.
9 Perform the spark test.
(See SPARK TEST ).
Is a strong blue spark visible at each cylinder?
Yes Go to the next step.
No Inspect or replace the malfunctioning parts, according to the inspection results.
10 Inspect CMP and CKP sensor for the following;

Is there any malfunction detected?
Yes Repair or replace the malfunctioning part according to the inspection results.
No Go to the next step.
11 Connect the M-MDS to the DLC-2.
Access and monitor the following PIDs using the data monitor function.
  • ECT
  • MAF
  • IAT
  • IAT2
  • APP
  • TP
  • MAP

Do the PIDs indicate correct values under trouble condition?
(See USING THE M-MDS ).
Yes Go to the next step.
No Inspect and repair or replace suspected parts and the related harnesses.
If the malfunction remains, perform the intermittent concern troubleshooting procedure.
(See INTERMITTENT CONCERN TROUBLESHOOTING ).
12 Access and monitor FUEL_PRES PID.
Is the FUEL_PRES PID value within the specification?
(See USING THE M-MDS ).
Yes Go to Step 16.
No Go to the next step.
13 Is the vehicle accelerate performance normally? Yes Go to the next step.
No Go to the Step 15.
14 Inspect the fuel pressure sensor.
(See FUEL PRESSURE SENSOR INSPECTION ).
Is the fuel pressure sensor normal?
Yes Go to Step 16.
No Replace the delivery pipe.
15 Replace the high pressure fuel pump.
Monitor FUEL_PRES PID.
Is the FUEL_PRES PID value within the specified?
(See FUEL PRESSURE SENSOR INSPECTION ).
Yes Troubleshooting is completed.
Go to Step 17.
No Go to the next step.
16 Measure compression pressure for each cylinder.
(See COMPRESSION INSPECTION ).
Are compression pressure within the specified?
Yes Inspect fuel injector for each cylinder.
(See FUEL INJECTOR INSPECTION ).
No Inspect following:
  • Damaged valve seat
  • Worn valve stem and valve guide
  • Worn or stuck piston ring
  • Worn piston, piston ring or cylinder
  • Improper valve timing

Service as necessary.
17 Verify test results.
  • If normal, return to the diagnostic index to service any additional symptoms.
  • If a malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform the repair or diagnosis.
    • If the vehicle is repaired, troubleshooting is completed.
    • If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.