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 Econoline, 1995 Ford Cutaway, and 1995 Ford Club Wagon. However, it is still accessible from the selected car via links, so may be relevant.

Perform this test when instructed by QUICK TEST or if directed by other test procedures. This test is only intended to diagnose:

CANP solenoid.
Harness circuits (CANP and VPWR).
Powertrain Control Module (PCM).

Fig 1: Canister Purge (CANP) Circuit

CANP WIRE COLOR & TEST PIN ID ⁽¹⁾

Application

Test Pin No.

Wire Color

MFI Models

Gray/Yellow

SFI Models

Gray/Yellow

⁽¹⁾	To determine if vehicle is equipped with MFI or SFI fuel system, see ENGINE/VIN ID article or appropriate wiring diagram in WIRING DIAGRAMS .

TEST PINS NO. 37 & 57 (VPWR) WIRE COLOR IDENTIFICATION

Application	Wire Color
All Models	Red

1) Check System Function

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 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 Solenoid For Vacuum Leaks

Turn ignition on. Leave CANP solenoid disconnected. Disconnect vacuum hose at CANP solenoid from manifold vacuum side of solenoid. Apply 16 in. Hg vacuum to manifold vacuum side of CANP solenoid. If CANP solenoid does not hold vacuum for 20 seconds, replace solenoid and repeat QUICK TEST. If fault is still present, service fuel evaporation canister or hoses. If CANP holds vacuum for 20 seconds, remain in output state DTM, leave vacuum pump attached and go to next step.

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 Supply To CANP Solenoid

Disconnect vacuum hose from CANP solenoid on manifold vacuum side. Start engine. If vacuum is present at vacuum hose, engine control system is okay. Check evaporative canister. If vacuum is not present at hose, check vacuum hose for improper routing, kinks and blockage. If hose is okay, check engine for mechanical cause of low vacuum.

6) Code 565 Or 569: Check VPWR To CANP Solenoid

Code 565 or 569 indicates fault in CANP solenoid circuit. Possible causes for this fault are:

Faulty CANP solenoid.
Open or short circuit in wiring harness.
Faulty PCM.

Turn ignition off. Disconnect CANP solenoid connector. Measure voltage between negative battery terminal and VPWR circuit terminal at CANP solenoid vehicle wiring harness connector. If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, repair open VPWR circuit. Reconnect components and repeat QUICK TEST.

7) Check CANP Resistance

Turn ignition off. Measure resistance between CANP solenoid terminals. If resistance is 30-90 ohms, go to next step. If resistance is not 30-90 ohms, replace CANP solenoid and repeat QUICK TEST.

8) Check Continuity Of CANP Circuit

Turn ignition off. Disconnect CANP solenoid. Disconnect 60-pin PCM connector. Inspect connector for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (T83L-50-EEC-IV), leaving PCM disconnected. Measure resistance between CANP test pin (No. 11 or 31) at breakout box and CANP circuit terminal at CANP vehicle wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open circuit. Remove breakout box, reconnect all components, and repeat QUICK TEST.

9) Check CANP Circuit For Short To Ground

Turn ignition off. Disconnect scan tester from DLC, if applicable. With CANP solenoid disconnected, measure resistance between breakout box CANP test pin (No. 11 or 31) and test pins No. 40, 46 and 60. If all readings are more than 10,000 ohms, go to next step. If any reading is 10,000 ohms or less, repair short to ground. Remove breakout box, reconnect all components, and repeat QUICK TEST.

10) Check CANP Circuit For Short To Power

Turn ignition off. With CANP solenoid and PCM disconnected, measure resistance between breakout box CANP test pin (No. 11 or 31) and test pins No. 37 and 57. If all readings are more than 10,000 ohms, replace PCM. Remove breakout box, reconnect all components, and repeat QUICK TEST. If any reading is 10,000 ohms or less, repair short to power. Remove breakout box, reconnect all components, and repeat QUICK TEST.