Hey guys, and girls, Got a 625 code from the computer the other day. The truck shifts fine but hard in all gears. Code says the line pressure control driver is open in the ECC. Short of a wiring problem, which I have checked for days, any Ideas? ECC no good or problem in the trans. 94 F-150 I6 E40D. Thanks

 

E1 E4OD ELECTRONIC DIAGNOSTICS CHECK VEHICLE POWER (VPWR) TO SOLENOID


l Check to make sure transmission harness connector is fully seated, terminals are fully engaged in connector and in good condition before proceeding.

l Turn ignition Off.

CAUTION:
Remove heat shield from transmission before removing connector. Remove solenoid Body connector by pushing on center tab and pulling on wiring harness. Do not attempt to pry tab with a screwdriver. Reinstall heat shield after service.

l Disconnect transmission connector.




NOTE:
Refer to the schematic and charts preceeding this Pinpoint Test.

l Turn key On, engine Off.

l Measure the voltage between electronic pressure control power circuit at transmission harness connector, and chassis/battery ground.

l Is voltage greater than 10.5 volts?

Yes
GO to «E2».

No
SERVICE open in harness. RECONNECT all components. ERASE codes. REPEAT Quick Test.


PINPOINT TEST E: -- ELECTRONIC PRESSURE CONTROL (EPC) SOLENOID


E2 CHECK CONTINUITY OF SOLENOID SIGNAL AND VEHICLE POWER (VPWR) HARNESS CIRCUIT


l Turn ignition switch off.

l Disconnect powertrain control module. Inspect for damaged or pushed out pins, corrosion, or loose wires.

l Install Rotunda EEC-IV 60-Pin Breakout Box 007-00033 or equivalent. Leave powertrain control module disconnected.

NOTE:
Refer to the schematic and charts preceding this Pinpoint Test.

l Measure resistance between test pin 37/57 (gas), test pin 71, 97 (diesel) at Breakout Box and electronic pressure control power circuit at transmission harness connector.

l Measure resistance between test pin 38 or 81 (Diesel) at Breakout Box and electronic pressure control pin at transmission connector.

l Is each resistance less than 5.0 ohms?

Yes
GO to «E3».

No
SERVICE open circuit. REMOVE Breakout Box. RECONNECT all components. ERASE codes and REPEAT Quick Test.


PINPOINT TEST E: -- ELECTRONIC PRESSURE CONTROL (EPC) SOLENOID


E3 CHECK HARNESS FOR SHORT TO POWER OR GROUND


l Turn ignition switch off.

l Make sure Rotunda EEC-IV 60-Pin Breakout Box 007-00033 is installed, powertrain control module is disconnected.

l Make sure transmission connector is disconnected.



NOTE:
Refer to the schematic and charts preceding this Pinpoint Test.

l Measure resistance between electronic pressure control circuit test pin 38 or 81 (Diesel) and test pin 37/57 (gas), test pin 71, 97 (diesel) at the Breakout Box.

l Measure resistance between electronic pressure control circuit test pin 38 or 81 (diesel) and test pins 40/60, 46 or 77/103, 91 (diesel) at the Breakout Box.

l Is each resistance greater than 10,000 ohms?

Yes
GO to «E4».

No
SERVICE short circuit. REMOVE Breakout Box. RECONNECT all components. REPEAT Quick Test.


PINPOINT TEST E: -- ELECTRONIC PRESSURE CONTROL (EPC) SOLENOID


E4 TRANSMISSION FUNCTIONAL TEST


l Make sure the transmission harness connector is disconnected.

l Intall line pressure gauge at line tap on case.

l Install Transmission Tester 007-0085C.

l Set Bench/Drive switch to DRIVE mode.

l Rotate gear selector switch to 1st gear position.

l Using tests outlined under Transmission Tester Instructions, perform electronic pressure control solenoid function test.

l Does electronic pressure control (LED GREEN) activate when electronic pressure control switch is depressed?

l Observe line pressure on gauge while depressing electronic pressure control switch.

NOTE:
Vehicle must be running.

l Does the line pressure drop?

Yes
REPLACE powertrain control module. REPEAT Quick Test.

No
GO to «E5».


PINPOINT TEST E: -- ELECTRONIC PRESSURE CONTROL (EPC) SOLENOID


E5 CHECK RESISTANCE OF SOLENOID


CAUTION:
Be sure that tester power is OFF or damage to volt-ohmmeter may result.

l Connect volt-ohmmeter negative lead to vehicle power (VPWR) jack and positive lead to electronic pressure control (EPC) jack on tester.

-- This is to test electronic pressure control solenoid.

l Record resistance.

l Is the resistance between 3.0-5.0 ohms?



Yes
GO to «E6».

No
REPLACE solenoid body assembly. RECORD and ERASE codes. REPEAT Quick Test.



PINPOINT TEST E: -- ELECTRONIC PRESSURE CONTROL (EPC) SOLENOID


E6 CHECK SOLENOID FOR SHORT TO GROUND


l Check for continuity between engine ground (BAT-) and appropriate jack with a volt-ohmmeter or other low current tester (less than 200 milliamps).

l Connection should show infinite resistance (no continuity).

l Is there continuity?



Yes
REPLACE solenoid body assembly. RECORD and ERASE codes. REPEAT Quick Test.

No
GO to «Diagnosis by Symptom Routine» for diagnosis of electronic pressure control concerns.

 

Does it slam into drive and reverse and shift hard in every gear? You need to check codes. Mine was doing the same thing but showing code 622 and 625. Code 625 means line pressure is at max which would cause this issue. Trans filter is also very common about falling into bottom of pan

 

Yeah, that was TWELVE YEARS ago.

Check dates before resurrecting old posts and then, do so only if there something really important to respond to.