For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
DEFINITION: The LOCK and UNLOCK functions of all doors are inoperative when using one of the following: the door lock switches, the key cylinder lock switch, the keyless entry transmitter, or all 3. The automatic door lock features are also inoperative.
1 | Did you review the operation and perform the necessary inspections? | -- | Go to Step 2 | Go to Symptoms
2 | Are the door lock and unlock functions inoperative from keyless entry only (if not equipped go to step 3)? | -- | Go to Diagnostic System Check - Remote Keyless Entry | Go to Step 3
3 | Are the door lock and unlock functions inoperative from both door lock switches only? | -- | Go to Step 4 | Go to Step 5
4 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the BCM connector C2.
3. Using a DMM, check for an open and for a short to ground in circuits 194 and 195. Refer to Circuit Testing in Wiring Systems.

Is an open or short to ground present?

--

Go to Step 6

Go to Step 7

5 | Are the door lock and unlock functions inoperative from all key cylinders only (if not equipped go to step 9)? | -- | Go to Step 8 | Go to Step 9
6 | Repair a poor connection, open, or a short to ground in circuit 194 or circuit 195. Refer to Wiring Repairs or Connector Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 20 | --
7 | Replace the BCM. Refer to Body Control Module Replacement in Body Control Systems. Is the repair complete? | -- | Go to Step 20 | --
8 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the BCM connector C2.
3. Using a DMM, check for an open and for a short to ground in circuits 780 and 781. Refer to Circuit Testing in Wiring Systems.

Is an open or short to ground present?

--

Go to Step 10

Go to Step 7

9 |

1. The door locks are totally inoperative.
2. Press lock and then unlock on either door lock switch.
3. Remove the PWR LOCK fuse.
4. Inspect the PWR LOCK fuse.

Is the PWR LOCK fuse open?

--

Go to Step 11

Go to Step 12

10 | Repair a poor connection, open, or a short to ground in circuit 780 or circuit 781. Refer to Wiring Repairs or Connector Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 20 | --
11 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the BCM connector C1.
3. Connect a test lamp between B+ and the BCM connector C1 terminal H. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 18

Go to Step 19

12 |

1. Place the PWR LOCK fuse back in the fuse block.
2. Using a test lamp, probe between the BCM connector C1 terminal H and ground. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 13

Go to Step 14

13 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the BCM connector C1.
3. Connect a test lamp between B+ and the BCM connector C1 terminal C. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 15

Go to Step 16

14 | Repair a poor connection or open in circuit 1540. Refer to Wiring Repairs or Connector Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 20 | --
15 | Repair a short to ground in circuit 295. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 20 | --
16 |

1. Reconnect the BCM connector C1.
2. Using a test lamp, probe between the BCM connector C1 terminal C and ground. Refer to Circuit Testing in Wiring Systems.
3. Press either door lock switch to the lock position.

Does the test lamp illuminate?

--

Go to Step 17

Go to Step 7

17 | Repair a poor connection or open in circuit 295. Refer to Wiring Repairs or Connector Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 20 | --
18 | Repair a short to ground in circuit 1540. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 20 | --
19 | Repair a short to ground in circuit 294, circuit 295 or circuit 694. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 20 | --
20 |

1. Turn the ignition switch to the LOCK position.
2. Re-install the connectors/components that were removed.
3. Turn the ignition switch to the RUN position for 6 seconds.
4. Turn the ignition switch to the LOCK position.
5. Remove the BCM PRGRM fuse.
6. Turn the ignition switch to the ACC position. (The BCM sounds the chime a number of times equivalent to the BCM type installed on the vehicle).
7. Turn the ignition switch from the ACC position, to the LOCK position and back to the ACC position within 1 second. (The BCM sounds any DTCs stored).

Are there any BCM DTCs present?

--

Go to Diagnostic Trouble Code (DTC) List/Type in Body Control Systems

Go to Step 21

21 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2