The TCIL indicates overdrive cancel mode activated (lamp on), electronic pressure control circuit shorted or monitored sensor failure (lamp flashing). this is the bulletin I found. There is a problem in your unit.
|LAMP - FLASHING TRANSMISSION CONTROL |
INDICATOR LAMP (TCIL) WITH DIAGNOSTIC
TROUBLE CODES (DTCS) 62, 628 AND/OR 1728
STORED IN MEMORY
|^||TRANSMISSION - E4OD - FLASHING |
TRANSMISSION CONTROL INDICATOR LAMP
(TCIL) WITH DIAGNOSTIC TROUBLE CODES
(DTCS) 62, 628 AND/OR 1728 STORED IN MEMORY
1989-97 F SUPER DUTY, F-250 HD, F-350
1989-98 ECONOLINE, F-150, F-250 LD
This TSB article is being republished in its entirety to correct the vehicles listed.
Some vehicles may exhibit a flashing Transmission Control Indicator Lamp (TCIL) and Diagnostic Trouble Codes (DTCs) 62, 628, and/or 1728 may be stored in memory. These DTCs can be set by any internal transmission element slippage or potentially by torque converter slippage.
Refer to the following text when servicing these codes.
NOTE : WHEN SERVICING A VEHICLE WITH A FLASHING TCIL WITH DTCS 62, 628 AND/OR 1728, DO NOT REPLACE THE TORQUE CONVERTER UNLESS PROPER DIAGNOSIS HAS PROVEN THE TORQUE CONVERTER TO BE THE CAUSE.
Always verify the customer concern. Proper diagnosis for DTCs 62, 628 and/or 1728 may require talking to the customer to find out if there were any other symptoms associated with the TCIL flashing, (i.e., shift concerns, erratic/early/late, proper torque converter operation, etc.), prior to noticing the TCIL flashing.
Prior to transmission repairs for DTCs 62, 628 and/or 1728 or investigating other causes, repair all non-related transmission DTCs first, then repair all other transmission DTCs other than 62, 628 and/or 1728.
Some of the other causes that may result in DTCs 62, 628 and/or 1728 are as follows:
|^||Aftermarket modifications (i.e., performance enhancers, electrical modifications, etc.) |
|^||Missing shifts (some/all) |
|^||Transmission fluid leakage (internal and/or external) |
|^||Erratic shift timing |
|^||Valves, springs or retainers in the main control/accumulator body not assembled correctly, binding or sticking |
|^||Check balls missing and/or mislocated. Damaged, unable to seal/seat properly |
|^||Higher or lower than normal line pressure |
|^||Transmission fluid restrictions and/or level |
|^||Erratic/inoperative vehicle speed and/or rpm sensor |
|^||Poor engine performance concerns |
Any vehicle system concerns that could cause the strategy to detect a perceived internal slippage or change in the expected rpm of internal transmission rotating components may cause DTCs 62, 628 and/or 1728 to set.