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Home >> Mazda >> 2006 >> B3000 Base, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Symptom Troubleshooting - (3 Of 5) >> DTC Application Chart - Powertrain Control Module (Pcm) >> Camshaft Position (CMP) Sensor Malfunction
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Camshaft Position (CMP) Sensor Malfunction

DTC P0340 DETECTION CONDITION & POSSIBLE CAUSES

DTC P0340 CAMSHAFT POSITION (CMP) SENSOR MALFUNCTION
DETECTION CONDITION 
  • P0340 indicates camshaft position sensor circuit failure.
POSSIBLE CAUSE 
  • CMP circuit open
  • CMP circuit shorted to GND
  • CMP circuit shorted to PWR
  • SIG RTN circuit open
  • Damaged CMP sensor
  • Damaged CMP sensor shielding
  • Damaged powertrain control module (PCM)
HINT  CMP Sensor Description 
  • Magnetic transducer.
  • Detects the position of the camshaft and identifies when piston No. 1 is on its compression stroke. A signal is then sent to the PCM and used for synchronizing the firing of sequential fuel injectors.
DTC P0340 DIAGNOSTIC PROCEDURE

DTC P0340 CAMSHAFT POSITION (CMP) SENSOR MALFUNCTION
STEP INSPECTION ACTION
1
  • Was the PCM quick test performed?
Yes If engine starts, Go to next step.
If engine does not start, DTC P0340 is not the cause of the no start.
See GENERAL PINPOINT TEST 12: NO START .
No Perform PCM quick test. See PCM QUICK TEST  .
2 CLEAR AND ATTEMPT TO RE-GENERATE DTC P0340
  • Clear DTCs using PCM Reset Procedure.
  • Key on, engine running (KOER).
  • Increase engine rpm to greater than 1, 500 rpm for 10 seconds. Repeat two times.
  • Key OFF.
  • Retrieve continuous memory DTCs.
  • Is DTC P0340 present? 
Yes Go to next step.
No Fault is intermittent.
See GENERAL PINPOINT TEST 4: INTERMITTENT .
3 CHECK FOR OPEN CMP CIRCUIT BETWEEN PCM AND CMP SENSOR
  • Disconnect PCM and CMP sensor.
  • Install breakout box, leave PCM disconnected.
  • Measure resistance of CMP circuit between PCM test pin 85 and the CMP sensor harness connector.
  • Measure resistance of SIG RTN circuit between PCM test pin 91 and the CMP sensor harness connector.
  • Are resistance measurements less than 5.0 ohms? 
Yes Go to next step.
No Repair open circuit.
Go to step 8.
4 CHECK CMP FOR SHORT TO POWER
  • Connect CMP sensor.
  • Key on, engine off (KOEO).
  • Measure voltage between PCM test pin 85 (CMP) and PCM test pins 51 and 103 (PWR GND).
  • Key OFF.
  • Is voltage less than 1.0 V? 
Yes Go to next step.
No Repair short circuit.
Go to step 8.
5 CHECK CMP FOR SHORT TO GND
  • Disconnect CMP sensor.
  • Measure resistance between PCM test pins 85 (CMP) and PCM test pin 91 (SIG RTN).
  • Is resistance greater than 10K ohms? 
Yes Go to next step.
No Repair short circuit.
Go to step 8.
6 CHECK FOR SHORTS IN PCM
  • Connect PCM to breakout box.
  • Disconnect CMP sensor.
  • Measure resistance between CMP and SIG RTN at the CMP harness connector.
  • Is resistance greater than 500 ohms? 
Yes Go to next step.
No Replace PCM.
See POWERTRAIN CONTROL MODULE (PCM) REMOVAL / INSTALLATION .
Go to step 8.
7 CHECK CMP SENSOR OUTPUT
  • Connect CMP sensor.
  • Set multimeter to AC scale (to monitor less than 5.0 volts).
  • Measure voltage between PCM test pin 85 (CMP) and PCM test pin 103 (PWR GND) while running the engine at varying rpm.
  • Does AC voltage vary greater than 0.1 volt AC? 
Yes Replace PCM.
See POWERTRAIN CONTROL MODULE (PCM) REMOVAL / INSTALLATION .
Go to next step.
No Replace CMP sensor.
See CAMSHAFT POSITION (CMP) SENSOR REMOVAL / INSTALLATION - 2.3L for 2.3L engine.
See CAMSHAFT POSITION (CMP) SENSOR REMOVAL / INSTALLATION - 3.0L for 3.0L engines.
See CAMSHAFT POSITION (CMP) SENSOR REMOVAL / INSTALLATION - 4.0L for 4.0L engines.
Go to next step.
8 VERIFY TROUBLESHOOTING OF DTCs COMPLETED
  • Connect all disconnected connectors.
  • Clear DTCs from PCM memory using WDS or equivalent tester.
  • Perform PCM Quick Test.
  • Is same DTC present? 
Yes Replace PCM.
See POWERTRAIN CONTROL MODULE (PCM) REMOVAL / INSTALLATION .
Repeat PCM quick test.
No If any other DTC is present, Go to applicable DTC inspection. See DIAGNOSTIC TROUBLE CODE (DTC) INDEX - POWERTRAIN CONTROL MODULE (PCM) . If no DTC is present, troubleshooting is complete.