MIL ON, DTC $71 Set
NO: 14-10-96GROUP: Fuel
DATE: Oct. 4, 1996
SUBJECT:
MIL Light Illumination DTC $71 - Evap. Purge Flow Monitor Failure
MODELS:
1994 - 1997 (BR) Ram Truck
NOTE:
THIS BULLETIN APPLIES TO VEHICLES WITH GASOLINE ENGINES BUILT PRIOR TO AUGUST 15, 1996 (MDH 08-15-XX).
SYMPTOM/CONDITION:
A "MIL" light is illuminated, the vehicle operator may detect a fuel odor, or a rough engine idle may be experienced. For 1996 - 97 M.Y. vehicles, the "MIL light will be illuminated due to Diagnostic Trouble Code (HEX) $71 - "Evap Purge Flow Monitor Failure". For all vehicles (1994 thru 97), the technician will find that the duty cycle purge solenoid is stuck in the open position (constantly purging evaporative system vapors at idle and all other engine speeds).
DIAGNOSIS:
Using a DRB III, verify the presence of DTC $71 on 1996 and 1997 vehicles. For all vehicles, disconnect the electrical connection and both vacuum lines to the duty cycle purge solenoid (DCP). Determine if the DCP solenoid is stuck in the open position by applying vacuum to the engine port of the DCP. If vacuum cannot by held, the DCP solenoid is stuck open and proceed with the following Repair Procedures.
PARTS REQUIRED:
Built Prior to 12/01/95:
1 04669475 Duty Cycle Purge Solenoid
1 52127666 Rollover Valve
1 53030635 Vapor Harness
1 53030926 Canister, Vapor Carbon (1996 - 97 with a build date code of
1876, or later, heat stamped in to the bottom of the canister
housing)
or
1 53030381 Canister, Vapor Carbon (1994 - 95 with a build date code of
1876, or later, heat stamped in to the bottom of the canister
housing)
Built From 12/01/95 To 08/15/96:
1 04669475 Duty Cycle Purge Solenoid
1 53030635 Vapor Harness
1 53030926 Canister, Vapor Carbon (1996 - 97 with a build date code of
1876, or higher, heat stamped in to the bottom of the canister
housing)
REPAIR PROCEDURE:
This bulletin involves the replacement of the rollover valve, the duty cycle purge solenoid, the vapor harness, and the vapor carbon canister.
1. Disconnect the negative battery cable.
2. Disconnect the evaporative system vapor purge line from the engine throttle body.
3. Disconnect the electrical connection and all lines to the duty cycle purge solenoid. Remove the duty cycle purge solenoid.
4. Disconnect all lines to the vapor canister and remove the vapor canister.
5. Disconnect the vapor line from the vehicle fuel tank rollover valve.
6. With compressed air, thoroughly clean all evaporative system lines including, the throttle body-to-duty cycle purge solenoid line, the duty cycle purge solenoid-to-vapor carbon canister line, the vapor carbon canister-to-rollover valve line, and the canister-to-atmosphere line.
NOTE:
THE EVAPORATIVE SYSTEM MUST BE FREE OF ALL LOOSE CARBON PARTICLES, OTHERWISE THE DUTY CYCLE PURGE SOLENOID MAY AGAIN BECOME STUCK IN THE OPEN POSITION. MAKE SURE NO DIRT ENTERS THE LINES.
7. Inspect the throttle body port. Insert a thin wire into the throttle body evaporative purge port to make sure that there are no restrictions (carbon particles) present.
8. Connect the evaporative system purge line to the throttle body.
9. Replace the vapor harness. Be careful not to introduce dirt into the evaporative system.
10. Install the new duty cycle purge solenoid including both lines and electrical connection.
NOTE:
THE DUTY CYCLE PURGE SOLENOID HAS MARKINGS ON ITS HOUSING WHICH DENOTE CORRECT ORIENTATION. MAKE SURE IT IS POSITIONED RIGHT SIDE UP.
11. Install the vapor carbon canister to its bracket. Rotate the canister until the line fittings are in a horizontal position. Tighten the vapor carbon canister bracket bolt to 10 Nm (95 in. lbs.).
NOTE:
THE BUILD DATE CODE ON THE BOTTOM OF THE VAPOR CARBON CANISTER MUST BE 1876 OR LATER. THE "187" = 187th JULIAN DAY OF AND THE "6" = 1996.
12. Replace the vehicle rollover valve on vehicles built prior to 12/01/95 (MDH 12-01-XX). The 52127666 rollover valve housing will be black in color with a small white cap on the top.
13. Connect the evaporative system vapor line to the rollover valve.
14. If the "Check Engine" lamp is on due to DTC $71, record Freeze Frame Data and erase the fault code.
POLICY: Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No:
Vehicles Built Prior to 12/01/95 (Includes Roll over valve)
25-01-55-96 1.8 Hrs.
Vehicles Built Between 12/01/95 & 8/15/96
25-01-55-97 0.8 Hrs.
FAILURE CODE: P8 - New Part