Diagnostic Aids

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

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

For DTC P0340, check battery voltage. Voltage should be more than 11 volts. Turn ignition to START, engine should start to crank immediately.

Fig 1: Identifying Camshaft Position Sensor Test Circuits & Distributor Harness Connector Terminals

Courtesy of FORD MOTOR CO.

NOTE: For additional testing information, see DIAGNOSTIC AIDS .
1. 1) DTC P0340: Attempt To Start Engine
   DTC P0340 indicates either No. 1 position signal or 120 reference signal is not received by PCM for first few seconds during engine cranking. Either No. 1 (POS) or 120 (REF) signal is not received by PCM often enough while engine speed is higher than specified engine speed, or relation between No. 1 (POS) and 120 (REF) signal is not in normal range during specified engine speed. Possible causes are:
   • CMP circuit open, or shorted to GND or PWR.
   • Faulty CMP sensor.
   • Starter motor.
   • Starting system circuit.
   • Dead or weak battery.
   • Faulty PCM.

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

2. 2) Clear DTCs & Attempt To Reset DTC P0340
   
   Perform PCM reset procedure. See PCM RESET PROCEDURE . Start engine. Increase engine speed to 1500 RPM or more for 10 seconds. Repeat 2 times. Turn ignition on, engine off. Perform QUICK TEST  to retrieve all DTCs. If DTC P0340 is present, go to next step. If DTC P0340 is not present, fault may be intermittent. Go to TEST Z  , step  1), or go to INTERMITTENTS in TROUBLE SHOOTING - NO CODES - VILLAGER article.
3. 3) Check VPWR Circuit To CMP Sensor
   
   Turn ignition off. Disconnect CMP sensor connector. Turn ignition on. Using DVOM, measure voltage between negative battery terminal and VPWR circuit at CMP harness connector. See Fig 1. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, go to TEST B  , step  1).
4. 4) Check GND Circuit To CMP Sensor For Open
   
   Turn ignition off. Using DVOM, measure resistance of GND circuit (Black/Red wire) between CMP harness connector and chassis ground. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black/Red wire. See WIRING DIAGRAMS article.
5. 5) Check Continuity To PCM
   
   Ensure ignition is off. Disconnect PCM connector. Inspect connector for damage, pushed out pins, or corrosion. Repair as necessary. Using DVOM, measure resistance of CMP REF (White wire) and CMP (Orange wire) circuits between PCM harness connector and CMP harness connector. See Figure and Fig 1 . If both resistances are less than 5 ohms, go to next step. If either resistance is 5 ohms or more, repair open in affected circuit.
6. 6) Check CMP & CMP REF Circuits For Short To Power
   
   Using DVOM, measure resistance between VPWR circuits and CMP circuit, and CMP REF circuit at PCM harness connector. See PCM TERMINAL CIRCUIT IDENTIFICATION  table. See Figure and Fig 1 . If all resistances are more than 10 k/ohms, go to next step. If any resistance is 10 k/ohms or less, repair short between affected circuits. See WIRING DIAGRAMS article.
7. 7) Check CMP & CMP REF Circuits For Short To GND
   
   Using DVOM, measure resistance between GND circuits and CMP circuit, and CMP REF circuit at PCM harness connector. See PCM TERMINAL CIRCUIT IDENTIFICATION  table. See Figure and Fig 1 . If all resistances are more than 10 k/ohms, go to next step. If any resistance is 10 k/ohms or less, repair short between affected circuits.
8. 8) Check CMP Signal
   
   Reconnect CMP sensor harness connector. Connect a jumper wire between chassis ground and power relay coil circuit at PCM harness connector terminal No. 4 (White/Green wire). See Figure. Using DVOM, measure voltage between chassis ground and CMP circuit at PCM harness connector terminal No. 47 (Orange wire). If voltage reading is about 2.5 volts, replace PCM. If voltage reading is not about 2.5 volts, replace CMP sensor.