Neon L4-2.0L SOHC (1995)
PROM - Programmable Read Only Memory: All Technical Service Bulletins
PCM- Check Engine Light ON/Flash Code 31
NO: 18-26-94 Rev. A
GROUP: Vehicle Performance
DATE: Dec. 23, 1994
SUBJECT:
Check Engine Light On "Evap Purge Flow Monitor Failure" - Flash Code 31
THIS BULLETIN SUPERSEDES SERVICE BULLETIN 18-26-94 DATED DEC. 9, 1994 WHICH SHOULD BE REMOVED FROM YOUR FILES.
THE MODEL APPLICATION NOTE HAS BEEN REVISED. CHANGES ARE HIGHLIGHTED WITH **ASTERISKS**.
MODELS:
1995 (PL) Neon
NOTE:
THIS BULLETIN APPLIES TO VEHICLES BUILT ON OR AFTER AUG. 6, 1994 (MDH 08-06-XX) THROUGH NOV. 23, 1994 (MDH 11-23-XX),
**AND ALSO APPLIES TO ANY VEHICLE WHERE THE PCM WAS REPLACED USING SERVICE BULLETINS 18-18-94 OR 18-25-94.**
SYMPTOM/CONDITION:
Check Engine Light on, Diagnostic Trouble Code "Evap Purge Flow Monitor Failure" and/or Flash Code 31 is set.
DIAGNOSIS:
Using the Mopar Diagnostic System (MDS) or the Scan Tool (DRBIII) and appropriate Diagnostic Procedure Manual, verify that all engine systems are
functioning correctly. If Diagnostic Trouble Codes (DTC's) other than 31 are present, record them on the repair order for future reference and repair as
necessary.
Verify that the Purge System is functioning properly. Disconnect the purge solenoid hose at the canister. The line should be free of carbon pellets (a light
amount of dust is normal). Start the engine. After about 90 seconds, the Duty Cycle Purge Valve should start to cycle. At the open end of the hose one
should feel a steady stream of brief vacuum pulses in response to the pulsing of the valve. This is normal and the purge system is functioning properly. If
no other codes other than 31 are present, proceed with the following repair.
EQUIPMENT/PARTS REQUIRED:
REPAIR PROCEDURE:
This bulletin involves reprogramming the powertrain control module with new software.
NOTE:
THE MOPAR DIAGNOSTIC SYSTEM IS REQUIRED TO PERFORM THE FOLLOWING REPAIR. THE SYSTEM MUST BE OPERATING
WITH RELEASE 15 OR HIGHER INSTALLED.
This repair involves selectively erasing and reprogramming the Powertrain Control Module with new software (calibration change).
1.
Connect the MDS (Mopar Diagnostic System) and DRBIII (Scan Tool) to the vehicle and power them up.
2.
Use the arrow keys and select # 2 MDS DIAGNOSTICS on the DRBIII MAIN MENU Screen.
3.
Use the arrow keys and select DIAGNOSTIC MENU on the MDS, then press NEXT MENU.
4.
Use the arrow keys and select CONTROLLER PROGRAMMING on the MDS, then press NEXT MENU.
5.
Use the arrow keys and select PROGRAM CONTROLLER PART on the MDS, then press NEXT MENU.
