1966 Crown Coupe, 2016 200 S AWD, 1962 Lark Daytona V8.
Joined
·
17,316 Posts
It is very difficult to offer any help or diagnosis with the information given here. An intermittent lock-up converter that isn't putting the TCM into 'limp-in' (2nd gear) may be considered a soft failure. The TCM may not be seeing any conditions out of the ordinary and is carrying on without lock-up.
It could be because it thinks that the transaxle is too cold for lock-up if the ATF temperature sensor is sending wrong information, for example. If the TCM sees a believable value, it won't set a fault code unless that value goes against what another sensor is saying.
Any history on this vehicle in the way of TCM updates or transaxle repairs?
Any stored fault codes would help here. The faults won't light the 'ck eng' or 'service engine soon' light and would need an OBD I scan tool with the Chrysler-specific connector cable to read them. The scan tool could also tell what the ATF temperature sensor was reading.
If the TCM has the finned housing, it can be reflashed with the latest and greatest software (released in 1996?) which is highly recommended. It addressed many problems on the spot. The non-finned TCM's are basically throwaway.
It could be because it thinks that the transaxle is too cold for lock-up if the ATF temperature sensor is sending wrong information, for example. If the TCM sees a believable value, it won't set a fault code unless that value goes against what another sensor is saying.
Any history on this vehicle in the way of TCM updates or transaxle repairs?
Any stored fault codes would help here. The faults won't light the 'ck eng' or 'service engine soon' light and would need an OBD I scan tool with the Chrysler-specific connector cable to read them. The scan tool could also tell what the ATF temperature sensor was reading.
If the TCM has the finned housing, it can be reflashed with the latest and greatest software (released in 1996?) which is highly recommended. It addressed many problems on the spot. The non-finned TCM's are basically throwaway.