Diagnostic procedure

2010 Mazda 5 Sport, 2.3 L, StandardSECTION Diagnostic procedure
WARNING: This page is about a different car, the 2004 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.
DTC P0340 [L3] DIAGNOSTIC PROCEDURE

STEP INSPECTION ACTION
1 VERIFY FREEZE FRAME DATA HAS BEEN RECORDED 
  • Has FREEZE FRAME DATA been recorded?
Yes Go to the next step.
No Record FREEZE FRAME DATA on repair order, then go to the next step.
2 VERIFY RELATED REPAIR INFORMATION AVAILABILITY 
  • Check for related Service Bulletins and/or online repair information availability.
  • Is any related repair information available?
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.
3 VERIFY CMP SENSOR VOLTAGE 
  • Disconnect CMP sensor connector.
  • Connect voltmeter between CMP sensor connector terminals A and B (sensor-side).
  • Inspect the voltage in AC range while cranking the engine.
  • Is there any voltage?
Yes Go to the next step.
No Go to step 10.
4 INSPECT CMP SENSOR CONNECTOR FOR POOR CONNECTION 
  • Verify that the CMP sensor connector is connected securely.
  • Is connector normal?
Yes Go to the next step.
No Reconnect the connector, then go to Step 15.
5 INSPECT CMP CIRCUIT FOR SHORT TO POWER 
  • Turn ignition switch OFF.
  • Disconnect CMP sensor connector.
  • Turn ignition switch ON (Engine off)
  • Measure voltage between following and body ground at CMP sensor terminals A and B.
    • CMP sensor connector terminal A (harness-side)
    • CMP sensor connector terminal B (harness-side)
  • Is there any voltage?
Yes Repair or replace suspected harness, then go to Step 15.
No Go to the next step.
6 INSPECT CMP CIRCUIT FOR SHORT TO GROUND 
  • Inspect continuity between following terminal and body ground:
    • CMP sensor connector terminal A (harness-side)
    • CMP sensor connector terminal B (harness-side)
  • Is there continuity?
Yes Repair or replace suspected harness, then go to Step 15.
No Go to the next step.
7 INSPECT CMP CIRCUITS FOR SHORT CIRCUIT 
  • Inspect continuity between CMP sensor connector terminals A and B (harness-side).
  • Is there continuity?
Yes Repair or replace suspected harness, then go to Step 15.
No Go to the next step.
8 INSPECT POOR CONNECTION OF PCM CONNECTOR 
  • Disconnect PCM connector.
  • Inspect for poor connection (damaged, pulled-out terminals, corrosion, etc.).
  • Is there any malfunction?
Yes Repair terminal, then go to Step 15.
No Go to the next step.
9 INSPECT CMP CIRCUIT FOR OPEN CIRCUIT 
  • Inspect continuity between following circuits:
    • CMP sensor terminal A (harness-side) and PCM terminal 2 (1), 2M(2) (harness-side)
    • CMP sensor terminal B (harness-side) and PCM terminal 28(1), 2J(2) (harness-side)
  • Is there continuity?
Yes Go to Step 11.
No Repair or replace suspected harness, then go to Step 15.
10 INSPECT CMP SENSOR 
Yes Go to the Step 15.
No Replace CMP sensor and go to Step 15.
11 VERIFY CKP SENSOR INSTALLATION 
Yes Go to the next step.
No Reinstall CKP sensor and go to Step 15.
12 VERIFY VALVE TIMING MECHANISM INSTALLATION 
  • Verify valve timing mechanism installation for following parts:
    • Timing chain misinstallation
    • Loose camshaft sprocket lock bolt
    • Loose crankshaft pulley lock bolt
  • Is valve timing mechanism installed correctly?
Yes Go to the next step.
No Reinstall following parts and go to Step 15.
  • Timing chain
  • Camshaft sprocket
  • Crankshaft pulley
13 INSPECT STOPPER PIN MECHANISM 
  • Remove timing chain.
  • Inspect stopper pin. (See VARIABLE VALVE TIMING ACTUATOR INSPECTION [L3] .)
  • Is stopper pin mechanism normal?
Yes Go to the next step.
No Replace variable valve timing actuator, then go to Step 15.
14 INSPECT ROTOR POSITION 
  • Removal variable valve timing actuator. (See VARIABLE VALVE TIMING ACTUATOR REMOVAL/INSTALLATION [L3] )
  • Is rotor position at maximum valve timing retard?
Yes VARIABLE VALVE TIMING MECHANISM NORMAL 
NOTE:
  • This DTC detected by intermittent concern.
  • Intermittent concern might be removed by cleaning mode of variable valve timing control function.

Go to the next step.
No Replace variable valve timing actuator, then go to the next step.
15 VERIFY TROUBLESHOOTING OF DTC P0340 COMPLETED 
  • Make sure to reconnect all disconnected connectors.
  • Turn ignition switch to ON (Engine off).
  • Clear the DTC from the PCM memory using the WDS or equivalent.
  • Start engine.
  • Access MAF PID using the WDS or equivalent.
    NOTE:
    • MAF PID should indicate 1.95 g/s {0.25 lb/min.} or above  during this test
  • Is same DTC present?
Yes Replace PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION .)
No Go to the next step.
16 VERIFY AFTER REPAIR PROCEDURE 
Yes Go to the applicable DTC inspection. (See DTC TABLE .)
No Troubleshooting completed.
(1) California emission regulation applicable ATX model
(2) Except for California emission regulation applicable ATX model
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.