Chevrolet P/U
5.6L
Lights = Brake
codes = none
Rebuilt transmission twice in 10,000 miles
tip/donation= yes
tech = SF
question = When I bought the truck,the torque converter wasn't locking
up. After 2 rebuilds,I was made aware that there was no power going to
the converter.I have 3 wires going to the trans (4L-60)one is tan and
black,another is purple,and the third is blue.I hooked up the purple to
12V with a 15 amp fuse.I now have lock-up,but with any load,such as a
trailer,it won't stay locked.I also have oversized tires. By the way,it's a
2-wheel drive truck. The trans shop where I last had the tranny rebuilt
said it was because I had oversize tires and that I might try putting
a switched ground to manually lock -up. When I checked the other
wires,they were both hot with the key on but not running. Any help would be
appreciated.I just think I need the converter locked up so I don't burn up
another tranny.Thanks.
5.6L
Lights = Brake
codes = none
Rebuilt transmission twice in 10,000 miles
tip/donation= yes
tech = SF
question = When I bought the truck,the torque converter wasn't locking
up. After 2 rebuilds,I was made aware that there was no power going to
the converter.I have 3 wires going to the trans (4L-60)one is tan and
black,another is purple,and the third is blue.I hooked up the purple to
12V with a 15 amp fuse.I now have lock-up,but with any load,such as a
trailer,it won't stay locked.I also have oversized tires. By the way,it's a
2-wheel drive truck. The trans shop where I last had the tranny rebuilt
said it was because I had oversize tires and that I might try putting
a switched ground to manually lock -up. When I checked the other
wires,they were both hot with the key on but not running. Any help would be
appreciated.I just think I need the converter locked up so I don't burn up
another tranny.Thanks.
SF:
Thank you for our tip/donation.
It took me awhile to find the schematics i needed.
OK. The purple wire is what feeds the tcc solenoid. The purple gets its power from the
cruise/tcc/brake switch. That brake switch gets its power from the 'gauges' fuse. You need to
trace back from the transmission connector to the brake switch after making sure the gauges
fuse is good. If the fuse is good, and power is going to the brake switch, then power should be
going to the trans. (purple wire) . The brake switch is normally closed, and should be feeding
power to the trans. Since when you manually apply 12v to purple wire and tcc does work, then
that means the PCM is grounding the solenoid. With the brake light on the dash, that may be
the key to no power to purple wire. Either a faulty/misadjusted brake switch, or no power to the
brake switch.
There are several reasons the tcc will go off. Faulty TPS on the engine, 4th gear pressure
switch, weak tcc solenoid, etc. When the trans. Fluid temp gets too high, the PCM will command
tcc on to try to reduce heat. Since no power to purple wire for tcc and the other switches in
transmission that is the first thing to fix. The 4-3 downshifts switch will disengage tcc for a short
period of time when accelerating, until a steady engine speed and load is attained again. While
towing and hitting gas, or going uphill etc. TCC coming off then back on is a normal condition.
Oversized tires may just enhance that cycling. As stated above, need to get that purple wire
problem solved before all else. SF
Thank you for our tip/donation.
It took me awhile to find the schematics i needed.
OK. The purple wire is what feeds the tcc solenoid. The purple gets its power from the
cruise/tcc/brake switch. That brake switch gets its power from the 'gauges' fuse. You need to
trace back from the transmission connector to the brake switch after making sure the gauges
fuse is good. If the fuse is good, and power is going to the brake switch, then power should be
going to the trans. (purple wire) . The brake switch is normally closed, and should be feeding
power to the trans. Since when you manually apply 12v to purple wire and tcc does work, then
that means the PCM is grounding the solenoid. With the brake light on the dash, that may be
the key to no power to purple wire. Either a faulty/misadjusted brake switch, or no power to the
brake switch.
There are several reasons the tcc will go off. Faulty TPS on the engine, 4th gear pressure
switch, weak tcc solenoid, etc. When the trans. Fluid temp gets too high, the PCM will command
tcc on to try to reduce heat. Since no power to purple wire for tcc and the other switches in
transmission that is the first thing to fix. The 4-3 downshifts switch will disengage tcc for a short
period of time when accelerating, until a steady engine speed and load is attained again. While
towing and hitting gas, or going uphill etc. TCC coming off then back on is a normal condition.
Oversized tires may just enhance that cycling. As stated above, need to get that purple wire
problem solved before all else. SF
2002 chevy Silverado 1500. 4.8L V8.
Question: Transmissions slipping when getting off the highway and when coming to a stop then beginning
to move again.
Question: Transmissions slipping when getting off the highway and when coming to a stop then beginning
to move again.
Answer: First check the fluid level and condition. See if looks or
smells burned. Try a transmission flush service along with a filter
change. Just a filter change only removes about 4-5 quarts of
fluid, but the flush service replaces all fluid. If that does not help,
you may have a valve body problem internal to the trans.
Sticking valves can cause the feeling that it is falling into neutral.
smells burned. Try a transmission flush service along with a filter
change. Just a filter change only removes about 4-5 quarts of
fluid, but the flush service replaces all fluid. If that does not help,
you may have a valve body problem internal to the trans.
Sticking valves can cause the feeling that it is falling into neutral.
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