For 1990-2009 cars

Diagnostic tables provide a procedure that will help you locate the condition in a circuit that is causing a malfunction. All diagnostic procedures are symptom based, to assist you in locating the condition as fast as possible. Diagnostic tables should exist for all possible (realistic) symptoms and diagnostic trouble codes (DTCs).

#### Horns Inoperative

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
DEFINITION: Horns will not sound when horn button is pressed.
1 | Was the Diagnostic System Check performed? | -- | Go to Step 2 | Go to Horns System Check
2 |

1. Turn ignition switch to OFF.
2. Remove the horn relay.
3. Connect a fused jumper across the horn relay terminals 30 and 87.

Do the horns sound?

--

Go to Step 3

Go to Step 6

3 | Connect a test lamp between the horn relay terminals 85 and ground. Does the test lamp light? | -- | Go to Step 4 | Go to Power Distribution
4 |

1. Connect a test lamp between the horn relay terminal 86 and battery (B+).
2. Press and hold the horn switch.

Does the test lamp light?

--

Go to Step 5

Go to Step 11

5 | Replace the horn relay. Is the repair completed? | -- | Go to Horns System Check | --
6 | Connect a test lamp between the underhood junction block terminal A12 or B12 (CKT 29) and ground. Does the test lamp light? | -- | Go to Step 8 | Go to Step 7
7 | Replace the underhood junction block, refer to underhood junction block replacement. Is repair completed? | -- | Go to Horns System Check | --
8 | Connect a test lamp between the Ground Splice Pack G104 (CKT 250) and battery (B+). Does the test lamp light? | -- | Go to Step 9 | Go to Step 10
9 | Replace horns. Is repair completed? | -- | Go to Horns System Check | --
10 | Inspect G104 ground, if OK replace Ground Splice Pack G104. Is repair completed? | -- | Go to Horns System Check | --
11 |

1. Disconnect the underhood junction block connector C2.
2. Connect a test lamp between the underhood junction block terminal D1 and battery (B+).
3. Press and hold the horn switch.

Does the test lamp light?

--

Go to Step 7

Go to Step 12

12 |

1. Disconnect the Dash Integration Module (DIM).
2. Connect a test lamp between the underhood junction block terminal D1 and battery (B+).
3. Press and hold the horn switch.

Does the test lamp light?

--

Go to Step 13

Go to Step 14

13 | Replace the Dash Integration Module (DIM), refer to DIM replacement. Is the repair completed? | -- | Go to Horns System Check | --
14 |

1. Disconnect C202.
2. Connect a test lamp between connector C202 terminal B12 of the steering column side and battery (B+).
3. Press and hold the horn switch.

Does the test lamp light?

--

Go to Step 15

Go to Step 16

15 | Repair short to ground in CKT 28 (BLK). Is repair completed? | -- | Go to Horns System Check | --
16 | Repair open in CKT 28 in the steering column. Is the repair completed? | -- | Go to Horns System Check | --