Test D: Electronic Pressure Control Solenoid
WARNING: This page does not describe the selected car, but rather 11 other vehicles, including the 2002 Mercury Grand Marquis, 2002 Lincoln Town Car, 2002 Ford Crown Victoria, 2001 Mercury Mountaineer, and 2001 Mercury Grand Marquis. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
After each service or repair procedure has been completed, reconnect all components. Clear DTCs and repeat RETRIEVING DIAGNOSTIC TROUBLE CODES (QUICK TEST)
under SELF-DIAGNOSTIC SYSTEM. Ensure all EEC-V systems are working properly and DTCs are no longer present.
- Turn ignition switch to OFF position. Place gearshift lever in "P" position. Ensure transmission harness connector is fully seated, and terminals are fully engaged in connector and in good condition. Repair as necessary. Install scan tool. Turn ignition switch to ON position. Select DIAGNOSTIC DATA LINK, and then select PCM. Select ACTIVE COMMAND MODES, and then enter OUTPUT STATE CONTROL (OSC). Select TRANS-BENCH mode. If vehicle enters TRANS-BENCH mode, remain in TRANS-BENCH mode and go to next step. If vehicle will not enter TRANS-BENCH mode, repeat procedure. If vehicle is still unable to enter TRANS-BENCH mode, see SCAN TOOL UNABLE TO COMMUNICATE under SELF-DIAGNOSTIC SYSTEM.
- Install a 300 psi pressure gauge to EPC pressure port. See HYDRAULIC PRESSURE TESTS under PERFORMANCE TESTS. Start engine. While monitoring pressure gauge, enter a value between 15-90 in increments of 15, and then press SEND. Select a different value between 15-90, and then press SEND. Enter "XXX", press SEND and observe pressure gauge. EPC pressure should match value entered in psi (example: value 30 entered, gauge should read 30 psi). If EPC pressure is not as specified, go to next step. If EPC pressure is as specified, erase all trouble codes. See CLEARING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. Repeat QUICK TEST. See RETRIEVING DIAGNOSTIC TROUBLE CODES (QUICK TEST) under SELF-DIAGNOSTIC SYSTEM.
- Turn ignition switch to OFF position. Drain transmission fluid and remove oil pan. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Inspect internal molded lead frame and connectors for damage. Repair as necessary. Turn ignition switch to ON position. Using DVOM, measure voltage between internal molded lead frame terminal No. 4 and ground. See Fig 1 . If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open or short circuit. See WIRING DIAGRAMS . Erase all trouble codes. See CLEARING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. Repeat QUICK TEST. See RETRIEVING DIAGNOSTIC TROUBLE CODES (QUICK TEST) under SELF-DIAGNOSTIC SYSTEM.
- Using DVOM, measure voltage between internal molded lead frame terminals No. 4 and 6. See Fig 2 . Using scan tool, turn solenoids on and off. Ensure solenoids activate (click). While monitoring DVOM, select a value between 0-90 in increments of 15, and then press SEND. Select a different value between 0-90, and then press SEND. Enter "XXX", and press SEND to turn any activated solenoids off. If voltage and solenoid state changes, go to next step. If voltage or solenoid state does not change, check for open or short circuit in wiring harness between PCM and EPC solenoid.
- Disconnect transmission harness connector. Using DVOM, measure resistance between EPC solenoid terminals. See Fig 2 . Resistance should be 2.48-5.66 ohms. If resistance is as specified, go to next step. If resistance is not as specified, replace EPC solenoid. Erase all trouble codes. See CLEARING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. Repeat QUICK TEST. See RETRIEVING DIAGNOSTIC TROUBLE CODES (QUICK TEST) under SELF-DIAGNOSTIC SYSTEM.
- Using DVOM, check for continuity between each EPC solenoid terminal and ground. If continuity exists, replace EPC solenoid. If continuity does not exist, EPC solenoid circuit is okay. Diagnose by symptom. See SYMPTOM DIAGNOSIS (ELECTRONIC) or SYMPTOM DIAGNOSIS (MECHANICAL) under TROUBLE SHOOTING.