98 to later PCM=reverse lock problems
Thread Starter
Instructor
Joined: Sep 2007
Posts: 210
Likes: 4
From: Oro Valley AZ
98 to later PCM=reverse lock problems
Let me know if there is an easyer way to get the same results.
Since 98 reverselock is power on to unlock and later years are power off to unlock, making the whole PCM switch, re pinning, re programing et all not the end of the story. Seems to an old guy like me this whole system is one of those tecnology for tecnology's sake. Remember the T handles on some shifters? So for me a momentary on button type switch, like a PTT micriphone switch, providing power to the reverse solenoid does the trick. Anyone who has installed any aftermarket elec stuff could do the job. Tap into a switched 12v source, inline fuse if ya want, red button switch mounted on the shifter like a gun trigger hahahaha- wires down the tunnel to the solenoid and Ya got it. Spose a relay of some sort could be wired to reverse the power signal, or there may be a way to trick the PCM , or a roller tiped reed switch some where on the linkage. So how have you handled this without just removing the lock?
Since 98 reverselock is power on to unlock and later years are power off to unlock, making the whole PCM switch, re pinning, re programing et all not the end of the story. Seems to an old guy like me this whole system is one of those tecnology for tecnology's sake. Remember the T handles on some shifters? So for me a momentary on button type switch, like a PTT micriphone switch, providing power to the reverse solenoid does the trick. Anyone who has installed any aftermarket elec stuff could do the job. Tap into a switched 12v source, inline fuse if ya want, red button switch mounted on the shifter like a gun trigger hahahaha- wires down the tunnel to the solenoid and Ya got it. Spose a relay of some sort could be wired to reverse the power signal, or there may be a way to trick the PCM , or a roller tiped reed switch some where on the linkage. So how have you handled this without just removing the lock?
Tech Contributor
Joined: Jan 2007
Posts: 19,465
Likes: 1,167
From: Dyer, IN
Let me know if there is an easyer way to get the same results.
Since 98 reverselock is power on to unlock and later years are power off to unlock, making the whole PCM switch, re pinning, re programing et all not the end of the story. Seems to an old guy like me this whole system is one of those tecnology for tecnology's sake. Remember the T handles on some shifters? So for me a momentary on button type switch, like a PTT micriphone switch, providing power to the reverse solenoid does the trick. Anyone who has installed any aftermarket elec stuff could do the job. Tap into a switched 12v source, inline fuse if ya want, red button switch mounted on the shifter like a gun trigger hahahaha- wires down the tunnel to the solenoid and Ya got it. Spose a relay of some sort could be wired to reverse the power signal, or there may be a way to trick the PCM , or a roller tiped reed switch some where on the linkage. So how have you handled this without just removing the lock?
Since 98 reverselock is power on to unlock and later years are power off to unlock, making the whole PCM switch, re pinning, re programing et all not the end of the story. Seems to an old guy like me this whole system is one of those tecnology for tecnology's sake. Remember the T handles on some shifters? So for me a momentary on button type switch, like a PTT micriphone switch, providing power to the reverse solenoid does the trick. Anyone who has installed any aftermarket elec stuff could do the job. Tap into a switched 12v source, inline fuse if ya want, red button switch mounted on the shifter like a gun trigger hahahaha- wires down the tunnel to the solenoid and Ya got it. Spose a relay of some sort could be wired to reverse the power signal, or there may be a way to trick the PCM , or a roller tiped reed switch some where on the linkage. So how have you handled this without just removing the lock?
I wonder if anyone has even verified this operation?
The C5 parts manual calls for the same part number solenoid (12523300) from 97-2002.
The 97-2000 service manual states:
"When the Reverse Inhibit solenoid energizes, the operator can shift the transmission into reverse. The PCM enables the Reverse Inhibit solenoid whenever the vehicle speed is below 5 mph. When the vehicle speed is above 5 mph, the PCM de-energizes the solenoid, which prevents the operator from shifting the transmission into reverse."
While the 2001-04 service manual states:
"With the ignition ON, battery voltage is supplied directly to the reverse inhibit solenoid. At forward speeds above 5 kp/h (3 mph) the PCM grounds the control circuit of the reverse inhibit solenoid. This energizes the solenoid and mechanically blocks the shift lever from going into the REVERSE position."
So this begs the question: how can you have two distinctly different modes of operation, and only one part number for the solenoid?
In order for the solenoid to operate for a 97-2000 service manual description, the solenoid rod would have to compress the internal spring when energized(by the PCM providing a ground), and then the rod would be forced to it's fully extended position, when de-energized.......locking out reverse.
In order for the solenoid to operate for a 2001-04 service manual description, the solenoid rod would have to retracted in a de-energized state, and extended(pulling against the spring), in an energized state....locking out reverse. This makes the least amount of sense, because it would have the solenoid energized for 99% of the cars normal operation/driving time.
In any case, the way the service manual is written, suggests two distinct types of operation....and two distinct types of solenoids.....so the part numbers cannot be the same.......or the service manual is wrong.
Thread Starter
Instructor
Joined: Sep 2007
Posts: 210
Likes: 4
From: Oro Valley AZ
My observation-
My 98 solenoid is locked by spring inside with power off, With power applied the plundger retracts. All was fine with the 98 PCM, and locked at idle with the 2001 PCM
Tech Contributor
Joined: Jan 2007
Posts: 19,465
Likes: 1,167
From: Dyer, IN
1) Pin B, pink wire, 12 volts with key in "Run or Start"
2) Pin A, light green wire, resistance to ground with key in "Run or Start"
Tech Contributor
Joined: Jan 2007
Posts: 19,465
Likes: 1,167
From: Dyer, IN
Burning Brakes
Joined: Mar 2007
Posts: 840
Likes: 0
From: East Wenatchee Washington
this scares the crap out of me. i have had a PCM i bought from Trifecta Performance out of Seattle, and its been a few years since i bought it but now it makes me wonder if its worth the headache..
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Tech Contributor
Joined: Jan 2007
Posts: 19,465
Likes: 1,167
From: Dyer, IN
Which is exactly why I elaborated in post #2......because something does not make sense. If the later model PCM really did work opposite of the earlier years, then the part number must be different for the solenoid. It's not that big of a deal.
Instructor
Joined: May 2011
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From: Tampa Florida
