98 4R70W no drive

iraceitall · 01-22-2010, 10:28 PM

I just bought a 98 EB, 5.0/4R70W, with a little trans problem. Vehicle has 202k, trans was rebuilt 30K ago. It will not take off in D (sometimes briefly, then it kicks out), but goes in R, 1, or 2. No codes for engine or trans, O/D light does not flash, but have ABS codes C1102 (accelerator sensor) and C1230 (rear speed sensor circuit fault) Fluid is clean and full.

I had it in the shop and tried powerbraking against D, it engaged, but then as I revved to 2000 rpm, it kicked out. I let off the gas, and it engaged again, hard.

Any ideas?

iraceitall · 01-22-2010, 10:30 PM

No fluid leaks, range switch is secure and wiring good, neutral start switch works properly, no bad fuses or wiring I could see either...

*V8BoatBuilder* · 01-26-2010, 05:43 PM

Could it be a linkage problem, where the trans selector is straddling N and D?

iraceitall · 03-06-2010, 05:27 PM

After about 6 hours of online searching and phone calls, I decided to check the main pressure regulator valve in the valvebody, since the OE one is prone to wear. Sure enough it had a big worn spot. I ordered a new valve (Sonnax 76948-09) and gaskets, and it's working great!

01-22-2010, 10:28 PM	#1
iraceitall Wannabe Elite Explorer Montana 98 EB Join Date: Dec 2009 Posts: 7 Vehicle Specs (Original Poster)	98 4R70W no drive I just bought a 98 EB, 5.0/4R70W, with a little trans problem. Vehicle has 202k, trans was rebuilt 30K ago. It will not take off in D (sometimes briefly, then it kicks out), but goes in R, 1, or 2. No codes for engine or trans, O/D light does not flash, but have ABS codes C1102 (accelerator sensor) and C1230 (rear speed sensor circuit fault) Fluid is clean and full. I had it in the shop and tried powerbraking against D, it engaged, but then as I revved to 2000 rpm, it kicked out. I let off the gas, and it engaged again, hard. Any ideas?

01-26-2010, 05:43 PM	#3
V8BoatBuilder Transplanted Bostonian East Brunswick, NJ 97 Mountaineer V8 4x4 Join Date: Nov 2002 Posts: 3,429 Vehicle Specs	Could it be a linkage problem, where the trans selector is straddling N and D? __________________ -Aaron Off Road: 97' Mountaineer: V8, 4x4, 4.56s, 4" Superlift, SOA, TrXus 33x12.5 - Under The Knife Work: 00' Ranger 4cyl 5spd, 02' Ford E250 5.4 On Road: 2006 VW Jetta TDI/6spd DSG. Fill it with diesel, please. Octopus Yachts, LLC Engineered Marine Electrical Systems

03-06-2010, 05:27 PM	#4
iraceitall Wannabe Elite Explorer Montana 98 EB Join Date: Dec 2009 Posts: 7 Vehicle Specs (Original Poster)	UPDATE: fixed it! After about 6 hours of online searching and phone calls, I decided to check the main pressure regulator valve in the valvebody, since the OE one is prone to wear. Sure enough it had a big worn spot. I ordered a new valve (Sonnax 76948-09) and gaskets, and it's working great!

01-22-2010, 10:30 PM	#2
iraceitall Wannabe Elite Explorer Montana 98 EB Join Date: Dec 2009 Posts: 7 Vehicle Specs (Original Poster)	No fluid leaks, range switch is secure and wiring good, neutral start switch works properly, no bad fuses or wiring I could see either...