lambertius
Banned
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I wanted to make a video of this but I still look like I went 15 seconds with Mike Tyson (lets be honest, I probably wouldn't have even lasted that long) after getting my wisdom teeth yanked.
One of the (many) issues with my car was a transmission error code relating to there being a 'down switch absent' error code.
p1745 - Switch Up
p1748 - Switch Down
The symptoms of this code is that the transmission will:
-Hold in Auto mode
-Fail to change gear when pulling the lever
-Pulling the lever will trigger a CC error on the dash
-The car will refuse to go into reverse or neutral on command
My car had this issue in its service history on the Switch Up several years ago, and I have since gotten the same issue for Switch Down!
They resolved the issue by replacing the paddle assembly. Here is a picture of the wiring they cut up, fixing that is an adventure for another day!
You do not need to replace the paddle shifters to resolve the issue. The issue is a 'defective by design' problem can can be resolved by tightening a screw.
Step one is following the steps laid out here by our fearless leader to remove the paddles. https://www.sportsmaserati.com/index.php?threads/cruise-control-retro-fitting-guide.14692/
I dismantled the parts as much as I could to try and diagnose the issue, but fortunately you don't have to! The pictures below are just to help understand what is happening.
This rather clever little mechanism means that you never actually depress the buttons. The little spring on the circuit board is what presses the switches, this is why no matter how hard you pull you never break the switches! A cam motion from the lever is what controls the release of the spring.
These little switches aren't redundant, they both need to be depressed in order for a shift to take place. If only one is pressed the wrong value is sent to the TCU and an error code is generated.
I worked this out by making a little table of all the possible combinations below:
When I tested the same combinations using only one dip switch the results were different. Though I can't say exactly which combinations the TCU is monitoring, I can say that there is enough information that it would be able to determine that only one button is being depressed. So how is this happening?
You'll need to remove the larger of the two springs to get to this screw, but this is the culprit.
With the screw out of the way the issue becomes clear. The fitting is slotted, which over time allows movement in the circuit. As the circuit moves forward the spring that presses the buttons cannot correctly release and only presses on of the buttons, or activates with a significant delay triggering the error code. Loosening the screw, pushing the circuit as far back as possible and tightening it again resolves the problem.
Some high quality Italian workmanship I found while searching for the problem...
Decided to clean that up before reassembly!
One of the (many) issues with my car was a transmission error code relating to there being a 'down switch absent' error code.
p1745 - Switch Up
p1748 - Switch Down
The symptoms of this code is that the transmission will:
-Hold in Auto mode
-Fail to change gear when pulling the lever
-Pulling the lever will trigger a CC error on the dash
-The car will refuse to go into reverse or neutral on command
My car had this issue in its service history on the Switch Up several years ago, and I have since gotten the same issue for Switch Down!
They resolved the issue by replacing the paddle assembly. Here is a picture of the wiring they cut up, fixing that is an adventure for another day!
You do not need to replace the paddle shifters to resolve the issue. The issue is a 'defective by design' problem can can be resolved by tightening a screw.
Step one is following the steps laid out here by our fearless leader to remove the paddles. https://www.sportsmaserati.com/index.php?threads/cruise-control-retro-fitting-guide.14692/
I dismantled the parts as much as I could to try and diagnose the issue, but fortunately you don't have to! The pictures below are just to help understand what is happening.
This rather clever little mechanism means that you never actually depress the buttons. The little spring on the circuit board is what presses the switches, this is why no matter how hard you pull you never break the switches! A cam motion from the lever is what controls the release of the spring.
These little switches aren't redundant, they both need to be depressed in order for a shift to take place. If only one is pressed the wrong value is sent to the TCU and an error code is generated.
I worked this out by making a little table of all the possible combinations below:
When I tested the same combinations using only one dip switch the results were different. Though I can't say exactly which combinations the TCU is monitoring, I can say that there is enough information that it would be able to determine that only one button is being depressed. So how is this happening?
You'll need to remove the larger of the two springs to get to this screw, but this is the culprit.
With the screw out of the way the issue becomes clear. The fitting is slotted, which over time allows movement in the circuit. As the circuit moves forward the spring that presses the buttons cannot correctly release and only presses on of the buttons, or activates with a significant delay triggering the error code. Loosening the screw, pushing the circuit as far back as possible and tightening it again resolves the problem.
Some high quality Italian workmanship I found while searching for the problem...
Decided to clean that up before reassembly!