System Description
The body control module (BCM) diagnostic system check identifies conditions that are associated with the BCM. The following test is the starting point for any BCM concern or complaint. The test directs you to the next logical step in diagnosing the complaint.
The BCM is a reliable component and is not likely to cause the malfunction.
The following items cause most system complaints:
| • | Faulty wiring |
| • | Faulty connectors |
| • | Faulty components |
Understand the computer system and use the tables correctly in order to achieve the following results:
| • | Reduce diagnostic time |
| • | Prevent unnecessary parts replacement |
Diagnostic Aids
The following conditions may result in an intermittent operation of the BCM with no DTC stored:
| • | Any condition which results in the interruption of power to the BCM |
| • | Out of range battery voltage specification. Normal battery voltage is 9-16 volts. |
| • | A loose or damaged ground(s). |
It may be difficult to detect and accurately diagnose an intermittent failure in the electronic system. The BCM tests for the different malfunctions under different vehicle conditions. A test drive may cause a malfunction to repeat. If the system malfunction is not repeated during the test drive, a good description of the complaint may be useful in locating an intermittent fault condition.
Faulty electrical connections or wiring causes most intermittent problems. If you suspect an intermittent condition, inspect the suspected circuits for the following conditions:
| • | Poor mating of the connector halves or backed out terminals |
| • | Improperly formed or damaged terminals |
| • | Wire chafing |
| • | Poor wire to terminal connections |
| • | Dirty or corroded terminals |
| • | Damage to the connector bodies |
Use a J 35616-A for diagnostic procedures that require probing or testing a terminal. Use of the J 35616-A ensures the following results:
| • | No damage occurs to the terminal. |
| • | The tool determines if contact tension is sufficient. |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
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This step checks for DTC 12 and DTC 55. Both DTCs should always be displayed.
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This step checks for DTCs 25 and 35. Both DTCs should always be displayed for vehicles equipped with theft deterrent.
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This step checks for DTC 41. DTC 41 is displayed when any button is depressed on the remote control door lock transmitter and the system is functioning normally.
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This step checks for DTCs 42, 43, 44 and 45. One or more of these DTCs may be displayed when any button is depressed on the remote control door lock transmitter and the system is malfunctioning.
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This step checks for the remaining DTCs which may be displayed by the BCM.
Step | Action | Value(s) | Yes | No | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Enter the body control module (BCM) diagnostic mode. Refer to Diagnostic Trouble Code (DTC) Displaying . Are both of the following DTCs displayed?
| -- | Go to Step 2 | ||||||||||||||||||
2 | Is the vehicle equipped with content theft deterrent (CTD)? | -- | Go to Step 3 | Go to Step 6 | ||||||||||||||||
Are both of the following DTCs displayed?
| -- | Go to Step 4 | ||||||||||||||||||
Depress any button on the remote control door lock transmitter. Is DTC 41 displayed? | -- | Go to Step 5 | ||||||||||||||||||
Depress any button on the remote control door lock transmitter. Are any of the following DTCs displayed?
| -- | Go to Step 6 | ||||||||||||||||||
Are any of the following DTCs displayed?
| -- | Go to Step 7 | ||||||||||||||||||
7 | Were you sent here from another diagnostic table? | -- | Return to the diagnostic table | System OK |
