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 | Attempt to establish communication with the same system, same year, on a different vehicle. Can communication be established? | -- | Go to Step 4 | Go to Step 3
3 |

1. The scan tool may be inoperative.
2. Verify that the scan tool operates properly.

Does the scan tool operate properly?

--

Go to Step 4

Go to Scan Tool Inoperative .

4 |

1. Disconnect the theft deterrent module connector.
2. Use the DMM to measure the resistance between terminal 3 of the data link connector and terminal 8 of the theft deterrent module connector.

Is the measured resistance within the specified value?

Less than 5 ohms

Go to Step 6

Go to Step 5

5 |

1. Locate an open or a high resistance in circuit XM15.
2. Repair the open or the high resistance in circuit XM15

Is the repair complete?

--

Go to Step 15

--

6 | Use the DMM to measure the resistance between terminal 3 of the data link connector and a known good ground. Is the measure resistance within the specified value? | Less than 5 ohms | Go to Step 7 | Go to Step 10
7 |

1. Disconnect the sun roof actuator connector.
2. Use the DMM to measure the resistance between terminal 3 of the data link connector and a known good ground.

Is the measured resistance within the specified value?

Less than 5 ohms

Go to Step 9

Go to Step 8

8 |

1. There is an internal failure within the sun roof actuator that is pulling the circuit to ground.
2. Replace the sun roof actuator. Refer to Sunroof Actuator Replacement in Roof.

Is the replacement complete?

--

Go to Step 15

--

9 | If all of the modules are disconnected and there is still a short to ground, locate and repair a short to ground in the circuits. Is the repair complete? | -- | Go to Step 15 | --
10 | Use the DMM to measure the voltage between terminal 3 of the data link connector and a known good ground. Is the measure voltage within the specified value? | B+ | Go to Step 11 | Go to Step 14
11 |

1. Disconnect the sun roof actuator connector.
2. Use the DMM to measure the voltage between terminal 3 of the data link connector and a good ground.

Is the measured voltage within the specified value?

B+

Go to Step 13

Go to Step 12

12 |

1. There is an internal failure within the sun roof actuator that is pulling the circuit to B+.
2. Replace the sun roof actuator. Refer to Sunroof Actuator Replacement in Roof.

Is the replacement complete?

--

Go to Step 15

--

13 | If all of the modules are disconnected and there is still a short to B+, locate and repair a short to B+ in the circuits. Is the repair complete? | -- | Go to Step 15 | --
14 |

1. Use the DMM to check for proper voltage and ground circuits to the theft deterrent module.
2. If the voltage and ground circuits are OK, replace the theft deterrent module. Refer to Theft Deterrent Module Replacement in Theft Deterrent.

Is the replacement complete?

--

Go to Step 15

--

15 |

1. Connect all connectors and components that were disconnected.
2. Connect the scan tool.
3. Establish communication with the theft deterrent module.

Does the scan tool communicate with the theft deterrent module?

--

System OK

Go to Step 1