Diagnostic Aids

Perform this test only when directed by QUICK TEST or other test. This test is intended to diagnose the following:

• Camshaft Position (CMP) sensor.
• CMP, VPWR and GND harness circuits.
• PCM.

1. DTC P0340: Start Engine
   
   DTC P0340 indicates that PCM has detected Camshaft Position (CMP) sensor circuit failure. Possible causes for this fault are as follows:
   • CMP circuit open or shorted to ground.
   • CMP circuit shorted to power.
   • Faulty CMP sensor.
   • Open VPWR or GND circuit.
   • Faulty PCM.

   Attempt to start engine. If engine starts, go to next step. If engine does not start, go to step  3.

2. Clear DTCs & Attempt To Reset DTC P0340
   
   Clear PCM memory. Start engine. Increase engine speed to 1500 RPM or more for 10 seconds. Repeat 2 times. Perform QUICK TEST  to retrieve all DTCs. If DTC P0340 returns, go to next step. If DTC P0340 does not return, fault is intermittent. Go to TEST Z  or the appropriate TROUBLE SHOOTING - NO CODES - VILLAGER article.
3. Check VPWR Circuit
   
   Turn ignition off. Disconnect CMP harness sensor. See Fig 1. Turn ignition on. Measure voltage between ground and VPWR circuit at CMP harness connector. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, go to TEST B .
   Fig 1: Identifying Camshaft Position Sensor Test Circuits & Distributor Harness Connector Terminals

   Courtesy of FORD MOTOR CO.
4. Check Ground To CMP Sensor
   
   Turn ignition off. Measure resistance of GND circuit between CMP harness connector and ground. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, repair open in circuit.
5. Check Continuity To PCM
   
   Disconnect PCM harness connector. Inspect connector for damage, pushed out pins, or corrosion. Repair as necessary. Measure resistance of CMP REF and CMP circuits between PCM harness connector and CMP harness connector. See Fig 1. If both resistance measurements are less than 5 ohms, go to next step. If either resistance measurement is not less than 5 ohms, repair open in circuit(s).
6. Check For Short To Power
   
   Measure resistance between CMP and VPWR circuits at PCM harness connector. Measure resistance between CMP REF and VPWR circuits at PCM harness connector. If resistances are greater than 10 k/ohms, go to next step. If resistances are not greater than 10 k/ohms, repair short in affected circuit.
7. Check For Short To GND
   
   Measure resistance between CMP and GND circuits at PCM harness connector. Measure resistance between CMP REF and GND circuits at PCM harness connector. If resistance measurements are greater than 10 k/ohms, go to next step. If resistance measurements are not greater than 10 k/ohms, repair short in affected circuit.
8. Check CMP Signal
   
   Reconnect CMP sensor harness connector. Connect a jumper wire between ground and PCM power relay coil circuit. Measure voltage between ground and CMP circuit at PCM harness connector. If voltage reading is about 2.5 volts, replace PCM. If voltage reading is not about 2.5 volts, replace CMP sensor.