Mazda 6 Workshop Manual page 151

Diagnostic procedure
STEP
1 VERIFY FREEZE FRAME DATA HAS BEEN
RECORDED
• Has FREEZE FRAME DATA been recorded?
2 VERIFY RELATED REPAIR INFORMATION
AVAILABILITY
• Verify related service repair information
availability.
• Is any related repair information available?
3 VERIFY CURRENT SIGNAL STATUS: IS
CONCERN INTERMITTENT OR CONSTANT?
• Connect the WDS or equivalent to the DLC-2.
• Clear the DTC from the PCM memory using
the WDS or equivalent.
• Start the engine.
• Is the same DTC present?
4 INSPECT STARTER RELAY CONNECTOR FOR
POOR CONNECTION
• Turn the engine switch off.
• Inspect for poor connection (such as damaged/
pulled-out terminals, corrosion).
• Is there any malfunction?
5 DETERMINE IF MALFUNCTION IS IN ENGINE
SWITCH SIDE OR STARTER RELAY SIDE
• Turn the engine switch to the ON position
(Engine off).
• Measure the voltage between starter relay
terminal B and body GND.
• Is the voltage B+?
6 DETERMINE IF MALFUNCTION IS IN STARTER
RELAY OR PCM SIDE
• Turn the engine switch to the ON position
(Engine off).
• Measure the voltage between starter relay
terminal A and body GND.
• Is the voltage B+?
7 INSPECT ENGINE SWITCH CONNECTOR FOR
POOR CONNECTION
• Turn the engine switch off.
• Inspect for poor connection (such as damaged/
pulled-out terminals, corrosion).
• Is there any malfunction?
8 INSPECT ENGINE SWITCH SIGNAL CIRCUIT
FOR SHORT TO POWER SUPPLY
• Turn the engine switch to the ON position
(Engine off).
• Measure the voltage between engine switch
terminal A and body GND.
• Is the voltage B+?
9 INSPECT PCM CONNECTOR FOR POOR
CONNECTION
• Turn the engine switch off.
• Inspect for poor connection (such as damaged/
pulled-out terminals, corrosion).
• Is there any malfunction?
10 VERIFY TROUBLESHOOTING OF DTC P0512
COMPLETED
• Make sure to reconnect all disconnected
connectors.
• Clear the DTC from the PCM memory using
the WDS or equivalent.
• Start the engine.
• Is the same DTC present?
ON-BOARD DIAGNOSTIC
INSPECTION
Yes Go to the next step.
No Record the FREEZE FRAME DATA on the repair order,
then go to the next step.
Yes Perform repair or diagnosis according to the available
repair information.
• If the vehicle is not repaired, go to the next step.
No Go to the next step.
Yes Go to the next step.
No Intermittent concern exists.
Perform the "INTERMITTENT CONCERNS
TROUBLESHOOTING".
Yes Repair or replace the terminal, then go to Step 10.
No Go to the next step.
Yes Go to Step 7.
No Go to the next step.
Yes Go to Step 9.
No Inspect the starter relay, then go to Step 10.
Yes Repair or replace the terminal, then go to Step 10.
No Go to the next step.
Yes Repair or replace the wiring harness for a short to power
supply, then go to Step 10.
No Inspect engine switch, then go to Step 10.
Yes Repair or replace the terminal, then go to the next step.
No Repair or replace the wiring harness for a short to power
supply between starter relay terminal A and PCM terminal
78, then go to the next step.
Yes Replace the PCM, then go to the next step.
No Go to the next step.
ACTION
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