H - Memory Mirror Inoperative - Town Car
Pinpoint Test H: Memory Mirror Inoperajive - Town CarH1 - Set Memory Positions
- Sit down in driver's seat and close both front doors.
- Note position of both driver and passenger side mirrors.
- Press memory set button.
- Within 5 seconds, press Memory 1 button.
- Using mirror switch, move mirrors to a second position. Make sure there is movement on both mirrors, vertically and horizontally.
- Press memory set button.
- Within 5 seconds, press Memory 2 button.
Do mirrors move with switch?
YES GO to H2.
NO GO to Pinpoint Test B8 and execute through all. RETURN to H1 after addressing switch concerns. B - Both RH & LH Mirrors Inop. (Without Memory Mirrors)
H2 - Check Memory Position LED
- Press position switch 1. Press memory set switch.
- Within 5 seconds, press Memory 1 button.
Does memory LED turn on?
YES GO to H3.
NO SERVICE memory switch.
H3 - Check Memory Recall Of Programmed Position
- Press Memory 1 button.
Do mirrors move to exact position as set in step G1?
YES PRESS Memory 2 and 1 switch several times to make sure that operation is consistent. SYSTEM is operating normally.
NO GO to H4.
H4 - Check Memory Recall
- Press Memory 1 button.
Do mirrors move at all?
YES SERVICE memory recall.
NO GO to H5.
H5 - Checking Potentiometer Feedback Circuits
- Back probe connector C2 of driver's seat module at potentiometer inputs for motion which did not work.
Driver vertical pin C2-8, ckt 949 (R/W)
Driver horizontal pin C2-19, ckt 951 (DB/W)
Passenger vertical pin C2-17, ckt 957 (P/W)
Passenger horizontal pin C2-18, ckt 954 (DG/W)
Are all readings less than 0.5 volt?
YES CHECK circuit 958 (GY/R) for open to driver's seat module, or short to ground. RETEST system.
NO GO to H6.
H6 - Potentiometer Circuit 958 (GY/R) Voltage Low
- Follow steps in H5.
Are both circuits for one mirror less than 0.5 volt?
YES CHECK circuit 958 (GY/R) for open circuit to affected mirror. RETEST system.
NO GO to H7.
H7 - Potentiometer Circuits Voltage High And Low
- Follow steps in H5.
Is any circuit less than 0.5 volt?
YES CHECK affected circuit for open or damaged potentiometer. RETEST system.
NO GO to H8.
H8 - Potentiometer Circuit Voltage Constant
- Follow steps in H5.
Is any one circuit constant and between 0.5 and 4.5 volts?
YES REPLACE mirror. RETEST system.
NO GO to H9.
H9 - Potentiometer Circuit 955 (GY) Voltage High
- Follow steps in H5.
Do all circuits have 4.5 volts but not more than 5 volts? Yes
YES CHECK circuit 955 (GY) for open circuit. RETEST system.
NO GO to H10.
H10 - Potentiometer Circuit B+
- Follow steps in H5.
Do all circuits have more than 5 volts?
YES DISCONNECT connectors from driver seat module. CHECK all potentiometer circuits.
NOTE: Any of these circuits shorted to B+ will cause all motors to operate improperly during memory operation and all seat motors to "jog" during manual motion:
445 (O/LB), 449 (BR/PK), 452 (GY/R), 443 (LG/R), 442 (LG/O), 444 (LG/B K), 447 (O/R) and 446 (O/W).
To seat potentiometer, and circuits:
949 (R/W), 951 (DB/W), 954 (DG/W), 955 (GY), 957 (P/W) and 958 (GY/R).
To mirror potentiometer for short to B+. RETEST system.
NO REPLACE driver seat module. RETEST system.