VLKJ

Bad news - The leap-frog experiment coughed up a bug. We hooked up the 1996 ECU 89661-50303 (specified replacement part for early 96 LS400's per TSB EG002-97) to my 95 LS400. We immediately got a check engine light - emission control system. Otherwise, a short test drive was flawless. We put the old ECM back, the check engine light cleared, and I'm returning the 50303 ECM. (I noticed that the TSB for the 1996 LS didn't differentiate between national vs California vehicles, while the 1995 TSB did list both. So maybe the 96 ECM's got a "consolidated" calibration for the emissions system?) Good news - I walked through my experiment with Tracie at Our ECMS Company, Duryea PA, and today she is sending a replacement ECM 89661-50224 (specified replacement part for 95 LS400's per TSB EG003-96). If you want to try this route for obtaining an ECM, you can reach Tracie at 1-877-687-3267 or email AUTOECMS@AOL.COM or visit www.autoecms.com. Here's what I understand about their operation - they take in exchange units and reprogram them to the specified configuration (e.g. 89661-50220 or -50221 can be reprogrammed to be 89661-50224). The normal sequence is that when you order 50224, they use an exchangeable "core" already in their inventory, reprogram it and send it out. ECM cost is about $550 net ($650 less $100 back when you mail them your old ECM). Worst case, I suppose, is that if no corresponding core units are in stock, they will take your old ECM for reprogramming and send it back to you. This can be done pretty fast, apparently. NOTE: What you get from AUTOECMS is a black box ECM with a part number label, but without the original factory label. Since they're reprogramming the units, they remove the original labels. Anyway, there's the followup. Good luck! - Lee

1995ls400 - see the Throttle Position Sensor topic. I'm trying the 96 ECU in a 95 LS approach... Lee

Well, I may be able to provide some feedback on the 1995 ECU vs 1996 ECU questions. I've had occurrences of both 1995 problems - the low idle after high speed trips, and rough transmission shifts. My 1995 LS400 is in the (non-Dealer) shop today for 90k service (spark plugs will be replaced, but cruise control computer will remain). I'm having ECU part number 89661-50303 put in to replace the 1995 ECU. The 50303 ECU is the part specified as New Part Number for early production 1996 LS400's in Technical Service Bulletin EG002-97 (introduction: 1996 vehicles may experience an engine idle speed reduction just before stopping the vehicle after a continuous long drive). I'll post my test drive results (good or bad) over the next couple of days. If the 96 ECU in a 95 LS replacement works okay, I'll also post the site where I purchased the ECU $500-$600 range (w/12 month no-questions-asked return guarantee). Lee

Well, since your test drives have been trouble free, it is good to know that the ECM replacement by itself may cure both problems (downshifts/low idle). By not discussing the set (ECM, cruise, plugs) with you before they performed the service, the Houston service manager has snatched "an unhappily surprised customer" from the jaws of "a delighted customer" :D . Once a customer shows that he/she knows that TSB's exist, the dealers ought to just assume that the entire list will eventually surface, and talk through the options up front. Anyway, good luck to the svc mgr in your follow up discussion... Lee

Thanks for the road test followup, big50daddy, and congratulations on the improvements! Re: 1995 vs 1996 ECMs and drivability improvements...seems the problem of the rough transmission shifts was apparent to Lexus in the 1995 models, but maybe the connection to the idling-to-standstill wasn't made until the 1996 owners started reporting. Anyway, the TSB that applies to 1995 LS400 is recapped below. Technical Service Bulletin EG003-96 October 7, 1996 (OPCODE EG5002 requires the ECU replacement, cruise control computer, and spark plug replacements as a set for the 1995 LS400). LS400 DRIVABILITY IMPROVEMENT - To improve driving smoothness at speeds above 40 miles per hour, the following components have been changed. Applies to all 1995 vehicles from JT8UF22E*S0O: Old part / New part / Application 89661-50220 / 89661-50224 / ECM Fed. (veh prod 9410-9502) 89661-50221 / 89661-50224 / ECM Fed. (veh prod 9502-9507) 89661-50230 / 89661-50234 / ECM Cal. (veh prod 9410-9502) 89661-50231 / 89661-50234 / ECM Cal. (veh prod 9502-9507) 88240-50070 / 88240-50071 / Cruise Control Computer (veh prod 9410-9507) 90919-01180 / 90919-01178 / Spark Plugs (veh prod 9410-9507) Thanks, Lee

big50daddy - Have you had an opportunity to take your 95 LS400 on an extended drive after getting your new ECM installed last month? Has the new ECM solved your engine idle reduction/stall condition? To any techies - (1) TSB EG002-97 refers to a logic change for the 1996 LS400. To help with big50daddy's 95 LS400, this revised 96 logic must have been incorporated into the ECM replacement part for 95 models, or are the ECM's for both model years the same? (2) Since some, but not all, 1995/early 1996 LS400's experienced the idle reduction problem, does this mean that installing a used ECM for one of those models might or might not cure the condition?