Diagnostic Aids

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 1995 Ford RV Cutaway, 1995 Ford Pickup, 1995 Ford F-Super Duty, 1995 Ford Econoline, and 1995 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

CANP valve is controlled by the PCM. CANP valve is used to regulate the flow of fuel vapors from the EVAP canister to the fuel system. The CANP valve operates on manifold vacuum and a duty cycle from the PCM.

Perform this test when instructed by QUICK TEST. This test is only intended to diagnose:

CANP valve.
Faulty Powertrain Control Module (PCM).
Wiring harness circuits (CANP and VPWR).

Fig 1: CANP Circuit Schematic (7.5L)

Fig 2: Identifying CANP Valve Circuit & Connector Terminals (7.5L)

1) Code 565

Code 565 indicates failure in CANP valve. Possible causes for this fault are:

Faulty CANP valve.
Faulty vacuum hoses.
Open or short circuit in wiring harness.
Faulty Powertrain Control Module (PCM).

Turn ignition off. Enter output state Diagnostic Test Mode (DTM). See OUTPUT STATE DIAGNOSTIC TEST MODE (DTM) under ADDITIONAL SYSTEM FUNCTIONS. After output state DTM has been entered, disconnect CANP valve. Connect DVOM positive lead to VPWR circuit terminal (Red wire) and negative lead to CANP circuit terminal (Gray/Yellow wire) at CANP vehicle wiring harness connector. Set DVOM to 20-volt scale. Observe DVOM, and then depress and release throttle several times to cycle voltage output. If voltage output change is 0.2 volt or more, remain in output state DTM and go to next step. If voltage output change is less than 0.2 volt, go to step 6).

2) Measure CANP Valve Resistance

Leave ignition off and CANP valve connector disconnected. Measure resistance between CANP valve terminals. If resistance is not 30-36 ohms, replace CANP valve and repeat QUICK TEST. If resistance is 30-36 ohms, go to next step.

3) Check CANP Valve For Vacuum Leaks

Leave CANP valve connector disconnected. Remove vacuum hose from input port of CANP valve. See Fig 3 . Using a vacuum pump, apply 16 in. Hg to input port. Replace valve if it does not hold vacuum for 20 seconds. If valve holds vacuum for 20 seconds, remain in output state DTM and go to next step.

Fig 3: Locating CANP Valve Vacuum Input Port (7.5L)

4) Check CANP Valve Electrical/Mechanical Operation

Reconnect CANP valve connector. Ensure 16 in. Hg is applied to input port. Fully apply and release throttle. If vacuum is not released, replace CANP valve and repeat QUICK TEST. If vacuum is released, remove jumper wire between SIG RTN and STI terminals of DLC. Go to next step.

5) Check Vacuum At CANP Valve Input Port

Leave CANP valve wiring harness connected. Start engine and allow to idle. Remove CANP valve vacuum input hose. If vacuum is not present at hose, check hose for blockage, leaking or incorrect routing. If vacuum is present at hose, EEC system is okay. Testing is complete.

6) Check VPWR Circuit Voltage

Leave CANP valve connector disconnected. Turn ignition on. Measure voltage between negative battery terminal and VPWR circuit terminal at CANP valve vehicle wiring harness connector. If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 or less, repair open circuit. Repeat QUICK TEST.

7) Check CANP Circuit Continuity

Turn ignition off. Disconnect PCM 60-pin connector. Inspect connector for damaged pins, corrosion and loose wires. Repair as necessary. Install EEC-IV Breakout Box (T83L-50-EEC-IV), leaving PCM disconnected. Measure resistance between test pin No. 11 and CANP terminal of CANP valve vehicle wiring harness connector. If resistance is 5 ohms or more, repair open circuit. Remove breakout box, reconnect all components, and repeat QUICK TEST. If resistance is less than 5 ohms, go to next step.

8) Check For CANP Circuit Short To Power

Leave ignition off and CANP valve connector disconnected. Measure resistance between breakout box test pin No. 11 and pins No. 37 and 57. If any resistance is less than 10,000 ohms, repair short circuit. Remove breakout box, reconnect all components, and repeat QUICK TEST. If each resistance is 10,000 ohms or more, go to next step.

9) Check For Short To Ground

Leave ignition off and CANP valve connector disconnected. Measure resistance between breakout box test pin No. 11 and pins No. 40, 46 and 60. If any resistance is less than 10,000 ohms, repair short to ground. Remove breakout box, reconnect all components, and repeat QUICK TEST. If each resistance is 10,000 ohms or more, replace PCM and repeat QUICK TEST.