4l60e not getting command to shift
10-29-2013, 06:11 PM
#1
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Join Date: Mar 2007
Location: western maryland
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4l60e not getting command to shift
This has proven to be a problem with no solution in sight.. trans just will not go into od. It is a good trans, as it does have all gears (Local shop used a handheld to shift to 4th). They told me pcm was giving command to shift to 1 instead of 4. I thought either bad tune or entire pcm needed replaced, so I did both. I ordered a new pcm, tuned, from PcmForLess. Didn't make any difference at all. There aren't any obvious bad grounds or broken wires. Replaced map sensor after a new servo in the trans (compliments of Performabuilt). Still no od. Instead of going to 4th, it stays in 3rd. I let off, and it just drops to an idle and rolls. I put the car on the backburner for a while (bought a bike) but would really like to get this thing running again. This all started after the engine was out to do cam heads and upgraded to a Performabuilt stage 2. If anyone can think of something I might've missed please help, thank you!
10-30-2013, 01:28 PM
#3
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Location: western maryland
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Re: 4l60e not getting command to shift
Live diagnostics are showing when its time to go to 4th the pcm is commanding 1st. I'm not aware of any codes. That's why I thought the tune or the pcm itself was at fault
Last edited by wheelliftnpony; 10-30-2013 at 02:29 PM.
10-30-2013, 05:45 PM
#4
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Location: north Carolina
Posts: 563
Re: 4l60e not getting command to shift
My understanding is that there is some sensors in the transmission that could cause the
the transmission not to shift properly ... but most of the time its not the sensor and the pcm hardly
ever goes bad not to say it can't
Do you have a shift kit in the transmission ??
my car was having trouble shifting at wide open throttle took it back to the guy that tuned
the car I don't know what he did but it shifts fine now
the transmission not to shift properly ... but most of the time its not the sensor and the pcm hardly
ever goes bad not to say it can't
Do you have a shift kit in the transmission ??
my car was having trouble shifting at wide open throttle took it back to the guy that tuned
the car I don't know what he did but it shifts fine now
10-30-2013, 09:13 PM
#5
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Join Date: Oct 2004
Location: Florida
Posts: 1,228
Re: 4l60e not getting command to shift
You could have wiring issues with the map or tps, causing the pcm to calculate the engine load incorrectly. Also, check your trans temp value in the pcm, if it thinks it's super cold, it may not command OD.
Now when you say it's commanding 1st when it's time to go to 4th, does the pcm actually read 1st as the target gear? Just wondering how you came to that conclusion, especially if the trans isn't actually shifting back to 1st. 3rd to 1st would be quite abrupt and very recognizable.
If all else looks good and you have no trans codes stored, try a pressure manifold switch on the valve body. Like said, trans codes don't always light the SES
Now when you say it's commanding 1st when it's time to go to 4th, does the pcm actually read 1st as the target gear? Just wondering how you came to that conclusion, especially if the trans isn't actually shifting back to 1st. 3rd to 1st would be quite abrupt and very recognizable.
If all else looks good and you have no trans codes stored, try a pressure manifold switch on the valve body. Like said, trans codes don't always light the SES
Last edited by blown94; 10-30-2013 at 09:17 PM.
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