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 voltages across the mirrors. During memory recall, the MMM moves the mirror motors until the voltage across each potentiometer matches the recorded voltage. During normal operation, the mirror position sensors are checked against out-of-range limits.
Conditions for Running the DTC
DTCs B1982 and B1983 are not set.
Conditions for Setting the DTC
The outside rear view mirrors vertical or horizontal position sensor input voltage is less than 0.25 volts.
Action Taken When the DTC Sets
The memory mirror module (MMM) will disable the affected motor during memory recall.
Conditions for Clearing the DTC
| • | The memory mirror module (MMM) no longer detects the position sensor failure. |
| • | 50 consecutive ignition cycles have been recorded without the DTC being detected. |
Diagnostic Aids
| • | If DTC B2144 is set by itself, the Left Mirror Vertical Position Sensor Signal circuit may be open or short to ground. |
| • | If DTC B2146 is set by itself, the Left Mirror Horizontal Position Sensor Signal circuit may be open or short to ground. |
| • | If DTC B2148 is set by itself, the Right Mirror Vertical Position Sensor Signal circuit may be open or short to ground. |
| • | If DTC B2150 is set by itself, the Right Mirror Horizontal Position Sensor Signal circuit may be open or short to ground. |
| • | If DTCs B2144 and B2146 were set together, the 5 Volt Reference circuit between splice S225 and the LH outside mirror may be open. |
| • | If DTCs B2148 and B2150 were set together, the 5 Volt Reference circuit between splice S225 and the RH outside mirror may be open. |
| • | If DTCs B2144, B2146, B2148 and B2150 were all set, the following may have occurred: |
| - | The 5 Volt Reference circuit between the MMM and splice S225 may be open. |
| - | the 5 Volt Reference circuit may be short to ground. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
Tests for the proper operation of the circuit in the low voltage range.
-
Tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.
-
Tests for a short to voltage in the 5 volt reference circuit.
-
Tests for a high resistance or an open in the low reference circuit.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Outside Rearview Mirror Schematics | ||||
1 | Did you perform the Door Systems Diagnostic System Check? | -- | Go to Step 2 | |
2 |
Does the scan tool indicate that the mirror position parameter is within the specified range? | 0.25 - 4.75 volts | Go to Diagnostic Aids | Go to Step 3 |
Does the scan tool indicate that the mirror position parameter is less than the specified value? | 0.25 volts | Go to Step 4 | Go to Step 10 | |
Does the scan tool indicate that the mirror position parameter is greater than the specified value? | 4.75 volts | Go to Step 5 | Go to Step 8 | |
Does the voltage measure less than the specified value? | 4.75 volts | Go to Step 6 | Go to Step 7 | |
Does the resistance measure less than the specified value? | 5 ohms | Go to Step 12 | Go to Step 11 | |
7 | Test the 5 volt reference circuit of the appropriate mirror position sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 13 |
8 | Test the 5 volt reference circuit of the appropriate mirror position sensor for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 9 |
9 | Test the signal circuit of the appropriate mirror position sensor for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 13 |
10 | Test the signal circuit of the appropriate mirror position sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 13 |
11 |
Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 13 |
12 | Inspect for poor connections at the harness connector of the appropriate mirror position sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 14 |
13 | Inspect for poor connections at the harness connector of the memory mirror module (MMM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 15 |
14 | Replace the power mirror motor. Refer to Outside Rearview Mirror Motor Replacement . Did you complete the replacement? | -- | Go to Step 16 | -- |
15 | Replace the memory mirror module (MMM). Refer to Memory Mirror Module Replacement . Did you complete the replacement? | -- | Go to Step 16 | -- |
16 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
