Diagnostic System Check

A Diagnostic System Check - Power Seat Systems:

CIRCUIT DESCRIPTION
The Power Seats Systems Diagnostic System Check is an organized approach used in order to identify problems associated with the module. Use this diagnostic system check as the starting point for any Memory Seats Module (MSM) complaint. This diagnostic system check will direct you to the next logical step in diagnosing the complaint. The MSM is a very reliable component. The MSM is not the likely cause of the malfunction. Most system complaints are linked to faulty wiring, faulty connectors, and occasionally to faulty components. Understanding the computer system and using the tables correctly will reduce diagnostic time and prevent unnecessary parts replacement.

DIAGNOSTIC AIDS
^ The following conditions may result in an intermittent operation of the memory seats module (MSM) with no DTC stored:
- Any condition that results in the interruption of power to the MSM is present.
- Battery or ignition voltage is not within 9.0- 16.0 V
- A loose or damaged ground is present.
- An open or shorted serial data line is present.
^ An intermittent failure in the electronic system may be very difficult to detect and to accurately diagnose The MSM tests for different malfunctions under different vehicle conditions. For this reason, a thorough test drive is often needed in order to repeat a malfunction. If the system malfunction is not repeated during the test drive, a good description of the complaint may be very useful in locating an intermittent malfunction. Faulty electrical connections or wiring causes most intermittent problems. When an intermittent condition is suspected, inspect the suspected circuits for the following conditions:
- Poor mating of connector halves or backed out terminals
- Improperly formed or damaged terminals
- Wire chafing
- Poor wire to terminal connections
- Dirty or corroded terminals
- Damage to connector bodies
^ Use the J 35616-A whenever a diagnostic procedure requests probing or checking a terminal. Using this adapter ensures that no damage to the terminal will occur. Using this adapter will provide an idea of whether contact tension is sufficient.
^ If the DTC is a history DTC, the problem may be intermittent. Perform the tests shown while moving related wiring and connectors. This action often causes the malfunction to occur. Perform a thorough inspection of all related wiring and connectors pertaining to the history DTC stored.
^ Exit all of the scan tool tests before cycling the ignition switch from the OFF position to the ON position unless the scan tool instructions direct otherwise. Follow the operating instructions in the scan tool operator's manual. Failure to follow these instruction may result in the following conditions:
- DTCs may set.
- Vehicle system malfunctions may occur.
- False DTCs may set.
- Scan tool malfunctions may occur.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table:
1. This step determines if communication may be established with the memory seat module (MSM).
2. This step tests for stored MSM DTCs.
3. This step determines if communication may be established with other modules connected to the Class 2 serial data line.
4. This step tests for any open MSM power fuses.
5. This step tests the MSM power circuit. If the test light does not turn ON, an open is present in the MSM power circuit.
6. This step tests the MSM ground circuit. If the test light does not turn ON, an open is present in the MSM power circuit.