Where is the upshift delay switch over valve located?
The most common cause is a vacuum leak, hoses on the vacuum supply check valve going to the switchover valve. The switchover valve is mounted on the firewall behind the brake master cylinder. It has a black wire going to it (electrical) and a green hose (vacum). You can apply vacum to the green line to see if the upshift delay valve holds vacum.
What is the upshift delay code for automatic transmissions?
It is the upshift delay codes P1700 and P1701. These codes would only apply to the mechanically controlled automatic transmissions used before 1996. Those transmissions used a throttle pressure cable (control pressure) for determining shift points under various loading.
How does Mercedes Benz switchover valve control work?
In order to heat the CAT and reduce the cold running time, Mercedes used an electrically controlled, vacuum-operated bellcrank-type lever action to change the capabilities of the control pressure cable. In other words, when cold, vacuum at the switchover valve is switched to a vacuum chamber at the transmission end of the shift cable.
What does it mean when upshift delay is not working?
It simply means that the upshift delay function is not working. The s/o valve is cheap – less than $50, but the problem is 95% of the time a vacum leak in the switch over valve itself, which is located on the side of the transmission.
The most common cause is a vacuum leak, hoses on the vacuum supply check valve going to the switchover valve. The switchover valve is mounted on the firewall behind the brake master cylinder. It has a black wire going to it (electrical) and a green hose (vacum). You can apply vacum to the green line to see if the upshift delay valve holds vacum.
It is the upshift delay codes P1700 and P1701. These codes would only apply to the mechanically controlled automatic transmissions used before 1996. Those transmissions used a throttle pressure cable (control pressure) for determining shift points under various loading.
In order to heat the CAT and reduce the cold running time, Mercedes used an electrically controlled, vacuum-operated bellcrank-type lever action to change the capabilities of the control pressure cable. In other words, when cold, vacuum at the switchover valve is switched to a vacuum chamber at the transmission end of the shift cable.
It simply means that the upshift delay function is not working. The s/o valve is cheap – less than $50, but the problem is 95% of the time a vacum leak in the switch over valve itself, which is located on the side of the transmission.