Codes U1110 and U1120 and delayed shifting into 2nd gear?

Hi,

The U codes indicated are both related to wheel distance and speed. That is why the transmission is having trouble shifting. Also, one of the most common causes for these codes is a loss of power to the ABS module, which could explain why the light is on. The P0507 indicated a high idle which is likely caused by an engine vacuum leak. On these vehicles, it isn't uncommon for the PCV to fail. Here is a link to help locate a leak.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

So, the easiest thing is to check if the ABS module is getting power. If you look below, I attached a pic and highlighted three fuses. These are power supplies to the ABS module. I need you to check the fuses and confirm there is power to and from them. (Pic 2 shows the fuse locations in the under-hood power distribution box)

Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Let me know what you find.

Take care,

Joe

See pics below.

The error codes U1110 and U1120 in a 2010 Volkswagen Routan indicate issues with the communication between the vehicle's modules. U1110 refers to a loss of serial communication for the vehicle speed sensor, while U1120 indicates a loss of serial communication for the steering angle sensor.

These communication issues can potentially affect the transmission's shifting behavior, including delayed shifting into 2nd gear. When the communication between modules is disrupted, it can cause the transmission to go into a default mode, leading to shifting problems.

Here are a few possible causes for these error codes and the delayed shifting issue:

Faulty Speed Sensor: The loss of communication for the vehicle speed sensor (U1110) suggests a potential issue with the sensor itself or its wiring. A malfunctioning speed sensor can impact the transmission's ability to shift properly.

Faulty Steering Angle Sensor: The loss of communication for the steering angle sensor (U1120) indicates a potential problem with the sensor or its wiring. Although the steering angle sensor is not directly related to the transmission, it is part of the vehicle's overall communication system, and a disruption in this communication can affect the transmission's behavior.

Wiring or Connection Issues: Wiring problems, such as damaged or corroded wires or loose connections, can cause communication failures between modules. It's essential to inspect the wiring harness and connectors related to the speed sensor and steering angle sensor for any signs of damage or poor connections.

Faulty Module or Control Unit: A malfunctioning module or control unit responsible for handling the communication between sensors and the transmission could also be a possible cause. In this case, further diagnosis with specialized diagnostic equipment is needed to identify the exact faulty component.

To resolve these issues, it is recommended to take the following steps:

Inspect the wiring and connections related to the speed sensor and steering angle sensor for any signs of damage, corrosion, or loose connections. Repair or replace as necessary.

If the wiring appears to be in good condition, consider replacing the speed sensor and/or steering angle sensor if they are determined to be faulty.

Thank you for the response. I'll look into these issues and keep you updated on the status.

Hamisi

Hello guys! So, I replaced the ABS Control Module. That cleared up the speed and wheel sensor issues. Also, my catalytic converter was completely clogged which was causing the vehicle to lag up to 40 MPH. Replaced the converter which immediately cleared that issue. Vehicle seems to be running good now.

Hi,

Thanks for the update. I'm glad to know it's running well for you again.

Feel free to come back anytime in the future. You're always welcome here.

Take care and Happy 4th!!!

Joe