Diagnostic Aids

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

• Camshaft Position Sensor (CMP).
• Harness circuits: CMP, VPWR and GND.
• Powertrain Control Module (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 Powertrain Control Module (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 greater 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 sensor (distributor connector). See Fig 1. Also see CIRCUIT PIN IDENTIFICATION  table. Turn ignition on. Measure voltage at VPWR circuit (Black/White wire) between CMP harness connector and ground. If voltage is greater than 10 volts, go to next step. If voltage is less than 10 volts, go to TEST B .
   Fig 1: CMP Test Circuits & Distributor Harness Connector Terminals

   Courtesy of FORD MOTOR CO.
4. Check Ground To CMP Sensor
   
   Turn ignition off. Disconnect CMP sensor (distributor connector). Measure resistance of GND circuit (Black/Red wire) between CMP harness connector and negative battery terminal. If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, repair open GND circuit. Repeat QUICK TEST .
5. Check Continuity To PCM
   
   Turn ignition off. Disconnect CMP sensor. Disconnect PCM connector. Inspect connector for damage, pushed out pins, or corrosion. Repair as necessary. Measure resistance of CMP circuit (Orange wire) between PCM connector terminal No. 47 and CMP connector. Also measure resistance between CMP REF circuit (White wire) at harness connector and PCM connector terminal No. 40. If both resistance measurements are less than 5 ohms, go to next step. If either resistance measurement is greater than 5 ohms, repair open circuit. Restore wiring and repeat QUICK TEST .
6. Check For Short To Power
   
   Turn ignition off. Disconnect CMP sensor (distributor connector). Disconnect PCM. Measure resistance between PCM connector CMP terminal No. 47 (Orange wire) and VPWR terminal No. 66 (Black/White wire). Also measure resistance between PCM connector CMP REF terminal No. 40 (White wire) and VPWR terminal No. 66 (Black/White wire). If resistances are greater than 10 k/ohms, go to next step. If resistances are 10/k ohms or less, repair short to power in suspect circuit. Restore all electrical connections and repeat QUICK TEST .
7. Check For Short To GND
   
   Turn ignition off. Disconnect CMP sensor (distributor connector). Disconnect PCM. Measure resistance between PCM connector CMP terminal No. 47 (Orange wire) and GND terminal No. 39 (Black/Red wire). Also measure resistance between PCM connector CMP REF terminal No. 40 (White wire) and GND terminal No. 39 (Black/Red wire). If all resistance measurements are greater than 10 k/ohms, replace PCM. If all resistance measurements are 10 k/ohms or less, repair short to ground in CMP or CMP REF circuit. Restore wiring and repeat QUICK TEST .