Circuit Description
The memory mirror module (MMM) receives inputs from the mirror position sensors during the following functions:
| • | Memory recall |
| • | Memory seat |
| • | Easy exit |
The potentiometers in the position sensors vary in resistance as the motors move the mirror. The MMM receives a variable voltage input depending on the resistance of the potentiometer. During memory set, the MMM records the voltage across all of the mirrors. During memory recall, the MMM moves the mirror motors until the voltage across each potentiometer matches the voltage stored. During normal operation, the mirror position sensors are checked against out-of-range limits.
Conditions for Setting the DTC
| • | The DTC will set only if DTC B1982 or B1983 is not current. |
| • | When the MMM detects that the RH outside mirror vertical position sensor input voltage is equal to or greater than 4.75 volts, the MMM sets DTC B2149. |
Action Taken When the DTC Sets
When a position sensor DTC is set as current, the MMM will disable the affected motor during memory recall. The motor will remain enabled for manual position.
Conditions for Clearing the DTC
| • | The MMM does not detect the position sensor failure during the last monitoring cycle. |
| • | A history DTC will clear after 50 consecutive ignition cycles, if the condition for the malfunction is no longer present. |
| • | Use the On-Boards Clearing DTCs feature. |
| • | Use a scan tool. |
Diagnostic Aids
| • | If multiple mirror position sensor DTCs are set, test CKT 674 (YEL) for an open or a short. Test CKT 675 (LT GRN) for an open. |
| • | If one mirror position sensor DTC is set, test the wiring from the position sensor to the MMM. If the wiring is OK, replace the suspect mirror. The mirror position sensor wiring includes the following circuits: |
| - | Left vertical CKT 784 (DK GRN) |
| - | Left horizontal CKT 786 (GRY) |
| - | Right vertical CKT 787 (BRN) |
| - | Right horizontal CKT 785 (LT BLU/BLK) |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
Perform the Power Door Systems Diagnostic System Check.
-
This step tests the outside mirror for an internal short to power.
-
This step tests the position input circuit for a short to power.
-
Clear all of the DTCs after the repair procedure is complete.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Did you perform the Power Door Systems Diagnostic System Check | -- | Go to Step 2 | ||
Is the resistance within the specified range? | 0-5 ohms | Go to Step 3 | Go to Step 4 | |
Is the circuit OK? | -- | Go to Step 6 | Go to Step 5 | |
4 | Replace the MMM. Is the repair complete? | -- | Go to Step 7 | -- |
5 | Repair the short to power in CKT 787 (BRN). Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 7 | -- |
6 | Replace the RH outside mirror. Refer to Outside Rearview Mirror Motor Replacement . Is the repair complete? | -- | Go to Step 7 | -- |
Are all of the DTCs cleared? | -- | -- |
