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Horn System Cadillac SRX I

Horns 3 illustrations ~1125 words

Fastener Tightening Specifications

ApplicationSpecification
MetricEnglish
Horn and Bracket Assembly to the Body9 N.m80 lb in

Fastener Tightening Specifications

Horns Schematic Icons

Horns Schematic Icons Icon Icon Definition CAUTION: When performing service on or near the SIR components or the SIR wiring, the SIR system must be disabled. Refer to SIR Disabling and Enabling Zones. Failure to observe the correct procedure could cause deployment of the SIR components, personal injury, or unnecessary SIR system repairs

Scheme 1

Scheme 1: Horns Schematics
Scheme 1: Horns Schematics

Scheme 2

Scheme 2: Horns Component Views
Scheme 2: Horns Component Views
CalloutComponent Name
1Horns

Scheme 3

Scheme 3
Scheme 3
CalloutComponent Name
1Inflatable Restraint Steering Wheel Module/Horn Switch
2Steering Wheel Controls - Left
3Steering Wheel Controls - Right
4Steering Wheel Controls - Left Connector
5C208
6Steering Wheel
7Steering Column
8Inflatable Restraint Steering Wheel Module Coil
9Inflatable Restraint Steering Wheel Module Connector C1
10Inflatable Restraint Steering Wheel Module Connector C2
11C208
12Steering Wheel Controls - Right Connector

Horns Connector End Views

Horn Assembly Connector Part Information 15305086 2-Way F Metri-Pack 150 Series (BK) Pin Wire Color Circuit No. Function A BK 250 Ground B D-GN 29 Horn Control

Diagnostic Starting Point - Horns

Begin the system diagnosis with the Diagnostic System Check - Vehicle in Vehicle DTC Information. The Diagnostic System Check will provide the following information

  1. The identification of the control modules which command the system
  2. The ability of the control modules to communicate through the serial data circuit
  3. The identification of any stored diagnostic trouble codes (DTCs) and their status

The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located.

Symptoms - Horns

IMPORTANTReview the system operation in order to familiarize yourself with the system functions. Refer to Horns System Description and Operation .

Visual/Physical Inspection

  1. Inspect for aftermarket devices which could affect the operation of the horn system. Refer to «Checking Aftermarket Accessories»(/cadillac/srx/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__checking-aftermarket-accessories) .
  2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
  3. Perform the following if a horn buzzes or has a harsh tone: Inspect for debris in the joint where the horn fastens to the vehicle. Test the torque of the horn mounting hardware. The horn mounting hardware should be tightened to a torque of 10 N.m (7 lb ft).

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

  1. «Horns Always On»(/cadillac/srx/i-2003-2009/remont/horns/#horn-system)
  2. «Horns Inoperative»(/cadillac/srx/i-2003-2009/remont/horns/#horn-system)
  3. «Horns - Poor Tone»(/cadillac/srx/i-2003-2009/remont/horns/#horn-system__horns-poor-tone)

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 4: Tests if ground is constantly being applied to the horn relay.
  2. 5: The horn relay control circuit includes the horn slip ring and the horn switch. The horn slip ring and horn switch must be tested for a short to ground when testing the relay control circuit. Refer to «Circuit Testing»(/cadillac/srx/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing) and «Wiring Repairs»(/cadillac/srx/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs) in Wiring Systems.
StepActionYesNo
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the dash integration module (DIM) Horn Relay Output ON and OFF. Are the horns on at all times?Go to Step 3Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
3Turn OFF the ignition. Disconnect the horn relay. Are the horns on at all times?Go to Step 8Go to Step 4
4Connect a test lamp between the battery positive voltage circuit of the horn relay coil and the horn relay control circuit. Does the test lamp illuminate?Go to Step 5Go to Step 6
5Test the horn relay control circuit for a short to ground. The horn relay control circuit includes the horn slip ring and the horn switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 11Go to Step 7
6Inspect for poor connections at the horn relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 11Go to Step 9
7Inspect for poor connections at the harness connector of the DIM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 11Go to Step 10
8Repair the short to voltage in the horn control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 11
9Replace the horn relay. Did you complete the replacement?Go to Step 11
10IMPORTANT: Perform the DIM programming procedure when replacing the DIM. Replace the DIM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.Did you complete the replacement?Go to Step 11
11Operate the horns. Do the horns operate properly?System OKGo to Step 1
IMPORTANT
Perform the DIM programming procedure when replacing the DIM.

Horns Always On

The numbers below refer to the step numbers on the diagnostic table.

  1. 4: This step verifies that the dash integration module (DIM) is providing ground to the horn relay.
  2. 5: This step tests for voltage at the battery positive voltage terminal of the horn relay coil.
  3. 7: This step tests for voltage at the battery positive voltage terminal of the horn relay switch. The SEATS circuit breaker supplies power to the battery positive voltage terminal of the horn relay switch.
  4. 13: The horns need maximum current flow to operate properly. A high resistance, greater than 0.5 ohm, in the horn control circuit or the horn ground circuit could cause operating problems with the horns. Inspect the circuits for faults that would restrict current flow.
  5. 15: The horn relay control circuit includes the horn slip ring and the horn switch. The horn slip ring and horn switch must be tested for a high resistance, an open or a short to voltage when testing the relay control circuit. Refer to «Circuit Testing»(/cadillac/srx/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing) and «Wiring Repairs»(/cadillac/srx/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs) in Wiring Systems.
StepActionYesNo
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Depress the horn switch. Do the horns operate?Go to Step 3Go to Step 5
3Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the body control module (BCM) Horn Output ON and OFF. Do the horns operate?Go to Testing for Intermittent Conditions and Poor Connections in Wiring SystemsGo to Step 4
4Test the dash integration module (DIM) portion of the horn relay control circuit for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 21Go to Step 11
5Turn OFF the ignition. Disconnect the horn relay. Connect a test lamp between the battery positive voltage circuit of the horn relay coil and a good ground. Does the test lamp illuminate?Go to Step 6Go to Step 14
6Connect a test lamp between the battery positive voltage circuit of the horn relay coil and the horn relay control circuit. Depress and hold the horn switch. Does the test lamp illuminate?Go to Step 7Go to Step 15
7Connect a test lamp between the battery positive voltage circuit of the horn relay switch and a good ground. Does the test lamp illuminate?Go to Step 8Go to Step 16
8Momentarily connect a 15-amp fused jumper wire between the battery positive voltage circuit of the horn relay switch and the horn control circuit. Do the horns operate?Go to Step 12Go to Step 9
9Reconnect the horn relay. Disconnect either horn connector. Connect a test lamp between the horn control circuit and a good ground. Depress and hold the horn switch. Does the test lamp illuminate?Go to Step 10Go to Step 17
10Connect a test lamp between the horn control circuit and the horn ground circuit. Depress and hold the horn switch. Does the test lamp illuminate?Go to Step 13Go to Step 18
11Inspect for poor connections at the harness connector of the DIM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 21Go to Step 19
12Inspect for poor connections at the horn relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 21Go to Step 20
13Repair the high resistance in the horn control circuit or the horn ground circuit. A resistance as low as 0.5 ohm could cause operating problems with the horns. Also, though unlikely, it is possible that both horns are defective. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 21
14Repair the open or high resistance in the battery positive voltage circuit of the horn relay coil. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 21
15Repair the open or short to voltage in the horn relay control circuit. The horn relay control circuit includes the horn slip ring and the horn switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 21
16Repair the open or high resistance in the battery positive voltage circuit of the horn relay switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 21
17Repair the open or high resistance in the horn control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 21
18Repair the open or high resistance in the horn ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 21
19IMPORTANT: Perform the DIM programming procedure when replacing the DIM. Replace the DIM. Refer to Control Module References in Computer/Integrating Systems.Did you complete the repair?Go to Step 21
20Replace the horn relay. Did you complete the replacement?Go to Step 21
21Operate the horns. Do the horns operate properly?System OKGo to Step 1
IMPORTANT
Perform the DIM programming procedure when replacing the DIM.

Horns Inoperative

Horns - Poor Tone

StepActionYesNo
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Depress the horn switch. Do the horns have a harsh tone or buzzing?Go to Step 3Go to Symptoms - Horns
3Test the horn mounting hardware for adequate torque. Refer to Fastener Tightening Specifications . Inspect the horns for debris in the joint where the horns attach to the vehicle. Did you find and correct the condition?Go to Step 7Go to Step 4
4Perform the following for each of the horns: Disconnect the horn connector. Connect a 15-amp fuse jumper wire between the positive battery terminal and the control terminal of the horn. Connect another jumper wire between the negative battery terminal and the ground terminal of the horn. Does the horn have a harsh tone or buzzing?Go to Step 6Go to Step 5
5Repair the high resistance in the horn control circuit or the horn ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 7
6Replace the horn. Refer to Horn Replacement . Did you complete the replacement?Go to Step 7
7Operate the horns. Do the horns operate properly?System OKGo to Step 1

Horns - Poor Tone

Removal Procedure

  1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/srx/i-2003-2009/remont/hoistjack/#general-information) in General Information.
  2. Remove the lower air deflector. Refer to «Air Deflector Replacement - Front»(/cadillac/srx/i-2003-2009/remont/exterior-body-panels/#body-front-end) in Bumpers.
  3. Loosen the bolt (1) that secures the horn assembly (2) to the body 4 full turns.
  4. Grasp the horn assembly (2) on both sides and rock it back and forth in order to pull it forward on the stud.
  5. Slide the horn assembly (2) rearward in order to locate the stud in the large portion of the keyhole slot (4).
  6. Disconnect the horn electrical connector (3) from the horn assembly (2).
  7. Pull the horn assembly (2) outward in order to remove it from the vehicle.

Installation Procedure

  1. Connect the horn electrical connector (3) to the horn assembly (2).
  2. Install the stud of the horn assembly (2) into the large portion of the keyhole slot (4).
  3. Slide the horn assembly (2) forward in the keyhole slot (4).
  4. Tighten the bolt (1) in order to secure the horn assembly (2) to the body side rail. Tighten: Tighten the bolt to 9 N.m (80 lb in).
  5. Install the lower air deflector. Refer to «Air Deflector Replacement - Front»(/cadillac/srx/i-2003-2009/remont/exterior-body-panels/#body-front-end) in Bumpers.
  6. Lower the vehicle.

System Description

The horn system consists of the following components

  1. HORN fuse
  2. Horn relay
  3. Inflatable restraint steering wheel module coil
  4. Horn switch
  5. Horn assembly
  6. Dash integration module (DIM)

System Operation

The vehicle horn system is activated under the following conditions

  1. The horn switch is depressed.
  2. The body control module (BCM) commands the horns on. The BCM commands the horns on under any of the following conditions: When the content theft deterrent system detects a vehicle intrusion. For further information refer to «Content Theft Deterrent (CTD) Description and Operation»(/cadillac/srx/i-2003-2009/remont/door-locks-anti-theft-systems/#theft-deterrent-system__content-theft-deterrent-ctd-description-and) . When the keyless entry system is used to lock the vehicle, a horn chirp may sound to notify the driver that the vehicle has been locked. The notification feature may be enabled or disabled through personalization. For further information refer to «Keyless Entry System Description and Operation»(/cadillac/srx/i-2003-2009/remont/door-locks-anti-theft-systems/#keyless-entry-system) . When the OnStar® system is used to sound the horns if equipped. For further information, refer to «OnStar Description and Operation»(/cadillac/srx/i-2003-2009/remont/entertainment-systems/#cellular-communication-systems__onstar-description-and-operation) .

Circuit Operation

Battery positive voltage is applied at all times to the horn relay coil and the horn relay switch. Pressing the horn switch applies ground to the horn relay control circuit. The BCM may also apply ground to the horn relay control circuit as described above. When the horn relay control circuit is grounded, the horn relay is energized and battery positive voltage is applied to the horns through the horn control circuit. The horns sound as long as ground is applied to the horn relay control circuit.