B1720

DTC B1720

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC B1720
- Mirror Up and Down Control Switch Circuit

Circuit/System Description

The driver door module (DDM) supplies battery positive voltage to the power mirror switch. When the mirror direction switch is placed in the up or down position, the appropriate signal circuit is switched to battery voltage. The driver door module senses the voltage change and activates the selected outside rearview mirror in the appropriate direction.

Conditions for Running the DTC

* Battery voltage must be between 9-16 volts.
* The ignition switch is in the ON position.

Conditions for Setting the DTC

The DDM senses an active state on both the mirror switch up and down signal circuits greater than 3 seconds.

Action Taken When the DTC Sets

The DDM ignores the continuous inputs from the switch. The DDM will respond to all other valid switch inputs.

Conditions for Clearing the DTC

* A current DTC will clear when the fault is no longer present.
* A history DTC will clear after 40 malfunction-free ignition cycles.

Circuit/System Verification

Command the left and right outside mirror to move up, down, left and right using the mirror directional switch. The mirror should move in the commanded direction.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector X5 at the DDM.
2. Ignition ON, verify the scan tool Mirror Motor parameter is Idle.

^ If not the specified value, replace the DDM.

3. Ignition OFF, reconnect the harness connector X5 at the DDM.
4. Ignition ON, observe the scan tool Mirror Motor parameter while cycling the mirror directional switch between the up, down, left and right positions. The parameter should change between Idle, Up, Down, Left, and Right.

^ If the parameter does not cycle between the specified values, replace the outside rearview mirror switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Power Mirror Switch Replacement