For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Use a DMM in order to measure the voltage between B+ and DLC terminal 5. Is the voltage within the specified range? | B+ (9-14 V) | Go to Step 2 | Go to Step 3
2 | Inspect for a proper connection of the scan tool to the DLC. Is the connection OK between the scan tool and the DLC? | -- | Go to Step 6 | Go to Step 7
3 | Does the instrument cluster display work? | -- | Go to Step 4 | Go to Step 5
4 | Repair the poor connection or open in circuit 451 between the DLC and S215. Has the repair been made? | -- | Go to Step 17 | --
5 | Repair the poor connection or open in circuit 451 between S215 and G110. Has the repair been made? | -- | Go to Step 17 | --
6 | Use the scan tool in order to establish communication with the PCM on a different vehicle. Can communication be established with the scan tool? | -- | Go to Step 8 | Go to Step 9
7 | Repair the poor connection between the DLC and the scan tool. Is the repair complete? | -- | Go to Step 17 | --
8 |

1. Reconnect the scan tool to the DLC.
2. Turn the ignition switch to RUN.
3. Use a scan tool in order to establish communication with the Powertrain Control Module (PCM).

Can the scan tool communicate with the PCM?

--

Go to Step 10

Go to Step 11

9 | Determine if the scan tool is malfunctioning. Refer to the scan tool instruction manual for additional information. Is the action complete? | -- | Go to Step 17 | --
10 |

1. If malfunction is not present or intermittent, inspect the PCM connector for a poor connection, short to B+, or short to ground in CKT 1807.
2. Repair as necessary.

Is the action complete?

--

Go to Step 17

--

11 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the PCM connector C1 (V6 VIN K) or C2 (V8 VIN G).
3. Use a DMM in order to measure the resistance between the DLC terminal 2 and the DLC terminal 5.

Is the resistance the same as the specified value?

Infinite

Go to Step 12

Go to Step 13

12 |

1. Turn the ignition switch to RUN.
2. Use a DMM in order to measure the voltage between the DLC terminal 2 and the DLC connector terminal 5.

Is the voltage less than the specified value?

1 V

Go to Step 14

Go to Step 15

13 | Repair the short to ground in CKT 1807. Is the repair complete? | -- | Go to Step 17 | --
14 | Check continuity in circuit 1807 between the DLC terminal 2 and the PCM connector C1 terminal 59 (V6 VIN K) or connector C2 terminal 58 (V8 VIN G). Is there continuity? | -- | Refer to PCM | Go to Step 16
15 |

1. Turn the ignition switch to the OFF position.
2. Repair the short to voltage in CKT 1807.

Is the repair complete?

--

Go to Step 17

--

16 | Repair the poor connection or an open in CKT 1807. Is the repair complete? | -- | Go to Step 17 | --
17 |

1. Ensure that the ignition switch is in the OFF position.
2. Reinstall connectors/components removed.

Is the action complete?

--

Go to Data Link Communications System Check

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