1997 Ranger 4x4 XLT, 5R55E transmission.
While 4-wheeling in the beautiful Rockies, I needed engine breaking on a steep decline in 4 Low. I shifted from Drive to 1st. The transmission properly engaged manual 2nd and then manual 1st as soon as it was able. RPMs were around 4500 rpm when the transmission engaged 1st gear. Everything worked fine.
Several minutes later, the CEL came on (later determined to be P1762, Overdrive Band Failed Off). The transmission shifted properly for the next several hours, including Overdrive. I reset the code to see if it would re-appear. The next day, the CEL came back on and while in Drive, the transmission doesn't appear to be using 1st gear. It just mopes along in 2nd gear (apparently) until it gets up to a typical 2nd gear speed. It will then shift to 3rd properly.
Using this thread, I performed only TSB 03-22-10 several years ago. I did not change any other parts. The transmission has worked flawlessly since then, including a few instances of heavy towing. Yet that TSB appears to be the only one to reference P1762.
I reset the CEL again and the code has not returned. However, the truck still seems to have no 1st gear.
What do you think my problem is?
EDIT
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I ended up popping 6 more codes! I spent a couple days digging as deeply as I could into the valve body. Here's a list of the things I did. I didn't find any smoking guns, but whatever I did fixed the problem. Because every solenoid circuit showed a failure, my money's on the tarnished connector pins. Thank you for the wealth of info throughout this site. I'd venture to guess I saved around $500 in troubleshooting.
DTCs set in association with transmission problems:
- P0750—Shift Solenoid A Malfunction
- P0751—Shift Solenoid A CKT Performance or Stuck Off
- P0755—Shift Solenoid B Malfunction
- P0756—Shift Solenoid B CKT Performance or Stuck Off
- P0760—Shift Solenoid C Malfunction
- P0765—Shift Solenoid D Malfunction
- P1762—Manufacturer Control Transmission (O/D Band Fail Off)
Valve body solenoid resistance:
- EPC—4.5 Ohms
- SS2—25.8 Ohms
- SS4—25.5 Ohms
- TCC—9.9 Ohms
- SS1—25.7 Ohms
- SS3—25.4 Ohms
Other Checks:
- Activated shift solenoids with 12v for 10 seconds each. All “clicked” normally and held the proper position.
- Blew compressed air through shift solenoids to check for debris.
- Valve body solenoid o-rings O.k.
- Checked electrical continuity on wiring harness. All o.k. Also checked each pin against all others to check for short circuits. All o.k.
- Cleaned pins on external electrical connector. Some buildup noted on pins, enough to cause a couple continuity problems while checking with voltmeter unless the buildup was first scratched off.
- Added dielectric grease to pins.
- Removed & inspected connector/pins at connector next to shift linkage. Added dielectric grease to female connector.
- Transmission Fluid Temperature thermistor (in EPC connector) is 34K Ohms at 65°F and decreases properly when heat is applied.
- Turbine Speed Sensor—71.8 Ohms
- Valve body separator plate and gasket o.k.
- Inspected solenoid brackets. No incipient cracks.
- Only slight gray residue over internal parts and on fluid pan magnet. No other debris noted.
- Tightened Intermediate and Overdrive bands
- Swapped position of SS1 and SS2.
- Tightened 3 torx bolts on separator plate to 95 lb-in. Bolts did tighten a little.
- Reinstalled valve body & brought bolts up to 95 lb-in in three passes.
- Removed and inspected PCM connector and pins.
- Removed and inspected square connector and pins near EGR valve.
- Removed & inspected all diodes, relays, and fuses in under hood junction box.
- Removed & inspected all fuses in cab junction box.
- Tightened 3 visible grounding points in engine bay