P0700/P1776 Van stuck in low gear (intermittent)
#1
P0700/P1776 Van stuck in low gear (intermittent)
2000 Caravan 3.0L has intermittent CEL light that when lit, the van is stuck in low gear. The problem is intermittent, and the CEL will reset with code reader when the problem is not present. I have read that I should change filter/fluid and inspect for metal in the tranny pan. If the pan is clean, I should replace valve body.
Does anyone have any experience with this? I would like to verify the troubleshooting steps listed above, before replacing the valve body.
Does anyone have any experience with this? I would like to verify the troubleshooting steps listed above, before replacing the valve body.
#3
Okay, from what I've read, this is a fairly common issue, but I don't see any definite fixes. I'll try to give the whole story here. I got vehicles mixed up in my first post...it's a 1999 caravan, not a 2000. I've changed the filter and refilled with +3 fluid (Valvoline)within the last 5,000 miles for this problem, but up until now it's been very intermittent. Recently however, it's been setting a fault on just about every long trip. I've checked resistances from the TCM connector through the speed sensors, and also each solenoid in the solenoid pack. I didn't have any limits for the sensors or solenoids, but everything seemed consistent. All the connectors are now clean, and the harness also checked out ok - no opens, or shorts to ground, as far as I could tell. I also checked the ground pins in the 60 pin connector to ground, and that seemed okay too.
I can tell when it's going to fault when, after driving at highway speeds, it downshifts very hard as I'm approaching a light or stop sign. This hard downshift occurs between 3rd and 2nd gear. It will then stay in 2nd, set the CEL light, and will be sluggish when accelerating, probably because it's stuck in 2nd gear, and not in 1st. I understand this is just "limp home", or a fail safe mode that can usually be reset by shutting off and restarting the van. However, it will immediately fail again unless I let the van cool down. Since the fault relates to the L/R solenoid, I have a new solenoid pack on order. I've read in various places that there's a filter screen in the pack that can plug up. When the pack gets here and gets installed, I will try to update the results after driving the van awhile. Any other ideas or advice will be appreciated.
A question for Master Tech...is the valve body you referred to and the solenoid pack the same thing?
I can tell when it's going to fault when, after driving at highway speeds, it downshifts very hard as I'm approaching a light or stop sign. This hard downshift occurs between 3rd and 2nd gear. It will then stay in 2nd, set the CEL light, and will be sluggish when accelerating, probably because it's stuck in 2nd gear, and not in 1st. I understand this is just "limp home", or a fail safe mode that can usually be reset by shutting off and restarting the van. However, it will immediately fail again unless I let the van cool down. Since the fault relates to the L/R solenoid, I have a new solenoid pack on order. I've read in various places that there's a filter screen in the pack that can plug up. When the pack gets here and gets installed, I will try to update the results after driving the van awhile. Any other ideas or advice will be appreciated.
A question for Master Tech...is the valve body you referred to and the solenoid pack the same thing?
Last edited by sjwoody; 07-20-2009 at 12:54 AM. Reason: added a question
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#8
for the record and anyone else searching, my 99 threw the following codes:
P0700 Transmission fault
P0731 Gear ratio error in 1st
P1790 Fault immediately after a shift
P0720 Output speed sensor error
Last year this van went into limp home mode, was stuck in 2nd and no speedo reading. replaced output speed sensor and solved problem
due to recent VSS sensor replacement, that was last on my list of suspects until codes were pulled. yanked the sensor and the tip of the plastic was broken off, fluid up around the magnet and one side of the magnet had a notch in it (not sure if that is from the factory).
replaced with an OEM version (same price as jobber) and symptoms are gone, van drives normal now. its an easy swap, 10 mm wrench (ratcheting is nice) or socket, 1 inch open ended wrench or deep socket for the sensor, slot screwdriver to loosen air intake hose clamps.
Wayne in Calgary
P0700 Transmission fault
P0731 Gear ratio error in 1st
P1790 Fault immediately after a shift
P0720 Output speed sensor error
Last year this van went into limp home mode, was stuck in 2nd and no speedo reading. replaced output speed sensor and solved problem
due to recent VSS sensor replacement, that was last on my list of suspects until codes were pulled. yanked the sensor and the tip of the plastic was broken off, fluid up around the magnet and one side of the magnet had a notch in it (not sure if that is from the factory).
replaced with an OEM version (same price as jobber) and symptoms are gone, van drives normal now. its an easy swap, 10 mm wrench (ratcheting is nice) or socket, 1 inch open ended wrench or deep socket for the sensor, slot screwdriver to loosen air intake hose clamps.
Wayne in Calgary