B1620 Fault Code

Long Description

Fault code B1620 is a manufacturer-specific body system code that represents an issue with the rear wiper switch circuit. This code will be logged when the body control module (BCM) has detected an open circuit condition in the rear wiper limit circuit.

An open circuit condition occurs when there is a break in the circuit somewhere. This can be from a failed component or bad wiring. Whatever the reason, an open circuit prevents the flow of current in the circuit.

In the rear wiper circuit, an open circuit condition will prevent the rear wiper from working.

This is a manufacturer-specific code, so not all vehicles will have a code B1620 that represents this issue. Toyota and Hyundai are two of the most commonly reported manufacturers to have this issue.

Other Signs of This Problem

There are relatively few additional signs of this issue. This is because the wiper circuit is a closed system. It is also a relatively unimportant one at that.

It is possible that the Check Engine light will be on in some cases.

Additionally, the rear wiper will not work properly. This is the easiest way to determine the B1620 fault code’s issue.

There may be other rear wiper codes logged as well. These can range from B1611 through to B1622. Front wiper codes start at B1840.

What Could Be The Problem?

The potential causes for this issue are specific to the rear wiper circuit and are all electrical in nature.

Anything that causes an open circuit has the ability to cause this fault code to be logged.

The first and most likely issue is that the limit switch for the rear wiper is defective or damaged. This will create an open circuit condition in the wiper circuit. The rear wiper motor could also be defective, but this code specifically relates to the switch.

Additionally, there may be a damaged electrical component in the wiring harness for the wiper rear switch. These could be things like damaged or frayed wires or loose connections.

In some instances, a faulty BCM can be the cause of this issue. However, this will likely come with a host of other body system fault codes being logged.

Fixes

The fixes for B1620 are focused on correcting the open circuit condition in the rear wiper limit circuit.

If the rear wiper switch is faulty, it must be replaced. The rear wiper motor should also be checked and replaced if it is faulty.

Damaged or frayed wires need to be repaired. Loose or damaged connections need to be fixed.

If there are issues with the BCM, it may need to be updated or replaced.

Seriousness

Fault code B1620 can be considered low in terms of seriousness. It does not pose any issue to the driveability of the vehicle. There is also no risk of damaging parts any further with this code.

It is a good idea to have this issue solved within a few weeks, particularly in rainy periods when the rear wiper will be used.