STEP/SEQUENCE RESULT WHAT TO DO NEXT TM 9-2320-363-20-1 Section 4 TROUBLESHOOTING CHARTS E.  FLASH CODE:    54 J1587 CODE: P84 12 - VEHICLE SPEED SENSOR FAULT 54-10 Check for Open Disconnect the ECM 5-way power Greater than VSS signal line (ckt #556) harness connector. 5 ohms or open. and/or (ckt #557) is open.  Repair Install a jumper wire between open.   Then go to 54-30. socket D of 5-way connector and socket E2 of ECM vehicle Less than or Problem appears to be with harness connector. equal to 5 ohms. device generating vehicle speed Find VSS end (non-ECM end) signal.  Refer to vehicle of the wire for (ckt #556). manufacturer's specifications/ Read resistance between this other recommendations regarding end of (ckt #556) and a good diagnosis and/or replacement ground. of vehicle speed signal Repeat measurements with generator. jumper between socket D of 5-way and socket E3. 54-30 Verify Repairs Turn Ignition off. (No Codes). Repairs are complete.  (Note: Reconnect all connectors. the only way to completely verify Turn ignition on. repair is by road testing it.  If Clear codes. you drive it on the road and Note status of "Check Engine" Code 84/9 returns, please review light. this section from first step to If "Check Engine" light does not find error. stay on, start engine and run until "Check Engine" light comes Code 84/9 (and All system diagnostics are on or for 1 minute. any other codes). complete.  Please review this Stop engine. section from start to find error. Read Inactive codes. Any other codes. Go to START-1, pg 3-345.41, except Code 84/9. to service other codes. Change 3  3-345.359