For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Data Link Connector System Check performed? | -- | Go to Step 2 | Go to Data Link Communications System Check
2 |

1. Connect the scan tool to another vehicle of the same model year in order to ensure the proper operation of the scan tool.
2. Turn the ignition switch to RUN.
3. Attempt to establish communication with the vehicle.

Does the scan tool communicate with the vehicle?

--

Go to Step 4

Go to Step 3

3 | The scan tool may be malfunctioning. Refer to the scan tool instruction manual. Ensure that the scan tool is functioning. Does the scan tool operate properly? | -- | Go to Data Link Communications System Check | --
4 |

1. Turn the ignition switch OFF.
2. Connect the scan tool to the original vehicle.
3. Verify that the scan tool connections are clean and tight.

Is the terminal contact between the DLC and the scan tool OK?

--

Go to Step 6

Go to Step 5

5 | Repair the terminal contact at the DLC. Is the repair complete? | -- | Go to Data Link Communications System Check | --
6 | Turn the ignition switch to RUN, with the engine OFF. Does the scan tool turn ON? | -- | Go to Step 13 | Go to Step 7
7 | Using a DMM, measure the voltage between DLC terminal 16 and the chassis ground. Is the voltage within the specified value? | 10-15 V | Go to Step 9 | Go to Step 8
8 | Repair the open or the short to ground in CKT 40 (ORN). Is the repair complete? | -- | Go to Data Link Communications System Check | --
9 | Measure the voltage from DLC terminal 16 to terminal 5. Is the voltage within the specified range? | 10-15 V | Go to Step 11 | Go to Step 10
10 | Repair the open in CKT 451 (BLK/WHT). Is the repair complete? | -- | Go to Data Link Communications System Check | --
11 | Repair the open in CKT 1250 (BLK). Is the repair complete? | -- | Go to Data Link Communications System Check | --
12 | Measure the voltage from DLC terminal 14 to ground. Is the voltage within the specified value? | 10-15 V | Go to Step 15 | Go to Step 13
13 | Measure the resistance from DLC terminal 14 to ground. Is the resistance within the specified range? | 0-5 ohms | Go to Step 22 | Go to Step 14
14 | Repair the open in CKT 835 (DK GRN) between DLC terminal 14 and C200 or the heater and the A/C programmer, if equipped. Is the repair complete? | -- | Go to Data Link Communications System Check | --
15 |

1. Disconnect the heater and A/C control assembly.
2. Measure the voltage from DLC terminal 14 to ground.

Is the voltage within the specified range?

10-15 V

Go to Step 17

Go to Step 16

16 | Replace the heater and A/C control assembly. Is the repair complete? | -- | Go to Data Link Communications System Check | --
17 |

1. Disconnect the radio.
2. Measure the voltage from DLC terminal 14 to ground.

Is the voltage within the specified value?

10-15 V

Go to Step 19

Go to Step 18

18 | Replace the radio. Is the repair complete? | -- | Go to Data Link Communications System Check | --
19 |

1. Disconnect the heater and A/C programmer.
2. Measure the voltage from DLC terminal 14 to ground.

Is the voltage within the specified range?

--

Go to Step 21

Go to Step 20

20 | Replace the heater and A/C programmer. Is the repair complete? | -- | Go to Data Link Communications System Check | --
21 | Repair the short to battery positive voltage (B+) in CKT 835 (DK GRN). Is the repair complete? | -- | Go to Data Link Communications System Check | --
22 |

1. Disconnect the heater and A/C control assembly.
2. Using a DMM, measure the resistance from DLC terminal 14 to ground.

Is the resistance within the specified range?

0-5 ohms

Go to Step 24

Go to Step 25

23 | Replace the heater and A/C control assembly. Is the repair complete? | -- | Go to Data Link Communications System Check | --
24 |

1. Disconnect the radio.
2. Measure the resistance from DLC terminal 14 to ground.

Is the resistance within the specified range?

0-5 ohms

Go to Step 25

Go to Step 26

25 | Replace the radio. Is the repair complete? | -- | Go to Data Link Communications System Check | --
26 |

1. Disconnect the heater and A/C programmer.
2. Measure the resistance from DLC terminal 14 to ground.

Is the resistance within the specified range?

0-5 ohms

Go to Step 27

Go to Step 28

27 | Replace the heater and A/C programmer. Is the repair complete? | -- | Go to Data Link Communications System Check | --
28 | Repair the short to ground in CKT 835 (DK GRN). Is the repair complete? | -- | Go to Data Link Communications System Check | --