Those with C6 Automatics experiencing Shift Interlock issues may encounter this unusual issue. Recently my '07 coupe has been having unusual shift interlock issues. It allowed me to shift to any gear with the engine off, yet with engine running not allowed. I have a emergency interlock cable but this was not activated or stuck.
By design one must apply and retain foot brake to start vehicle and to shift from Park to allow gear change. This safety feature is important. When shutting down, the shifter must be in Park. This is sensed by the electronics to allow shutdown. If not in Park, a message appears on the DIC "Shift To Park". There is a micro switch inside the front of the shifter housing which is activated when the lever is forward in Park.
In my case, whenever I shifted to Park, it sensed the function and allowed shutdown. However, in my case this was intermittent. Sometimes releasing pressure on the shifter handle disengaged the switch. Since the switch was not in Park it sensed that it was in gear and engaged the interlock solenoid to allow shifts. Unusual and tricky to diagnose.
I had to replace my cupholder due to a deteriorated slider anyways so I removed the radio fascia for that and then the shifter area for testing.
I traced the microswitch wiring and connected a test meter and saw the switch properly close with shifter handle forward, but when I took my hand off the handle, switch opened. See the attached document below(also added to the DORD Sticky above) page 6 for a photo of this switch. Note it's marked Park Position Solenoid, but should be appended "Switch". The author stated that in his post when he provided the document.
The switch wiring comes out to these connectors. The smaller to the interlock solenoid, the other(below it) from the microswitch. That bare wire is my emergency release cable which is hidden in the center console.
C6Shifter_0029.jpgC6Shifter_0031.jpgC6Shifter_0013.jpg
I was able to bend the switch lever slightly rearward to correct the fault. The lever is hardened steel so I used 2 small needle nose pliers to adjust. After the repair the shift interlock system now worked properly.
===
BTW, You cannot just buy the cupholder slider. Entire cupholder is available in repro. GM no longer stocks.
Original
C6Shifter_0019.jpg C6Shifter_0016.jpg
Replacement
C6Shifter_0087.jpgC6Shifter_0086.jpg
While I was in there I also fixed a few broken plastic console pieces from the last visit inside the console for other issues. I was a bit aggressive the last time by the looks of it. I decided to repair using my superglue and baking soda fix. More on that later in another thread....HERE.
Rich
By design one must apply and retain foot brake to start vehicle and to shift from Park to allow gear change. This safety feature is important. When shutting down, the shifter must be in Park. This is sensed by the electronics to allow shutdown. If not in Park, a message appears on the DIC "Shift To Park". There is a micro switch inside the front of the shifter housing which is activated when the lever is forward in Park.
In my case, whenever I shifted to Park, it sensed the function and allowed shutdown. However, in my case this was intermittent. Sometimes releasing pressure on the shifter handle disengaged the switch. Since the switch was not in Park it sensed that it was in gear and engaged the interlock solenoid to allow shifts. Unusual and tricky to diagnose.
I had to replace my cupholder due to a deteriorated slider anyways so I removed the radio fascia for that and then the shifter area for testing.
I traced the microswitch wiring and connected a test meter and saw the switch properly close with shifter handle forward, but when I took my hand off the handle, switch opened. See the attached document below(also added to the DORD Sticky above) page 6 for a photo of this switch. Note it's marked Park Position Solenoid, but should be appended "Switch". The author stated that in his post when he provided the document.
The switch wiring comes out to these connectors. The smaller to the interlock solenoid, the other(below it) from the microswitch. That bare wire is my emergency release cable which is hidden in the center console.
C6Shifter_0029.jpgC6Shifter_0031.jpgC6Shifter_0013.jpg
I was able to bend the switch lever slightly rearward to correct the fault. The lever is hardened steel so I used 2 small needle nose pliers to adjust. After the repair the shift interlock system now worked properly.
===
BTW, You cannot just buy the cupholder slider. Entire cupholder is available in repro. GM no longer stocks.
Original
C6Shifter_0019.jpg C6Shifter_0016.jpg
Replacement
C6Shifter_0087.jpgC6Shifter_0086.jpg
While I was in there I also fixed a few broken plastic console pieces from the last visit inside the console for other issues. I was a bit aggressive the last time by the looks of it. I decided to repair using my superglue and baking soda fix. More on that later in another thread....HERE.
Rich
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