B2336

B2336-HORN CONTROL CIRCUIT LOW





For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.

- When Monitored:
Continuously

- Set Condition:
When the Front Control Module (FCM) does not detect voltage on the (X4) Horn Relay Control circuit.





1. TEST FOR INTERMITTENT CONDITION
1. Turn the ignition on.
2. Using a scan tool, record and erase Diagnostic Trouble Codes (DTCs).
3. Operate the Horn Switch several times.
4. Cycle the ignition from on to off three times and leave on.
5. Using a scan tool, read DTCs.

Does the scan tool display DTC B2336-HORN CONTROL CIRCUIT LOW?

Yes

- Go To 2

No

- The conditions that caused this code to set are not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. CHECK FOR OPEN HORN FUSE




1. Inspect the Horn Fuse.

Is the fuse open?

Yes

- Go To 3

No

- Go To 9

3. REPLACE AND RECHECK HORN FUSE




1. Turn the ignition off.
2. Install a new Horn Fuse.
3. Turn the ignition on.
4. Operate the Horn Switch several times.
5. Inspect the Horn Fuse.

Is the fuse open?

Yes

- Go To 4

No

- Using the wiring diagram/schematic as a guide, inspect the wiring and connectors for the cause of the open fuse and repair as necessary.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

4. CHECK (A950) FUSED B(+) CIRCUIT FOR A SHORT TO GROUND




1. Turn the ignition off.
2. Remove the Horn Fuse.
3. Remove the Horn Relay.
4. Measure the resistance of the (A950) Fused B(+) circuit between ground and the Horn Relay connector.

Is the resistance below 10K Ohms?

Yes

- Replace the Integrated Power Module (IPM) and the Horn Fuse.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 5

5. CHECK (X2) HORN RELAY OUTPUT CIRCUIT FOR A SHORT TO GROUND




1. Disconnect the Horn 1 and Horn 2 connector.

NOTE: Check connectors. Clean and repair as necessary.

2. Measure the resistance of the (X2) Horn Relay Output circuit between ground and the Horn Relay connector.

Is the resistance below 10K Ohms?

Yes

- Go To 6

No

- Go To 7

6. CHECK (X2) HORN RELAY OUTPUT CIRCUIT IN IPM FOR A SHORT TO GROUND




1. Disconnect the IPM C2 connector.

NOTE: Check connectors. Clean and repair as necessary.

2. Measure the resistance of the (X2) Horn Relay Output circuit between ground and the Horn Relay connector.

Is the resistance below 10K Ohms?

Yes

- Replace the Integrated Power Module (IPM) and the Horn Fuse.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Repair the (X2) Horn Relay Output circuit for a short to ground. Replace the Horn Fuse.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

7. CHECK FOR A SHORTED HORN RELAY
1. Reconnect the Horn 1 and Horn 2 connector.
2. Install a known good relay in place of the Horn Relay.
3. Install a new Horn Fuse.
4. Turn the ignition on.
5. Operate the Horn Switch several times.
6. Inspect the Horn Fuse.

Is the fuse open?

Yes

- Go To 8

No

- Replace the original Horn Relay.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

8. CHECK FOR A SHORTED HORN




1. Turn the ignition off.
2. Disconnect the Horn 1 connector.
3. Install a new Horn Fuse.
4. Turn the ignition on.
5. Operate the Horn Switch several times.
6. Inspect the Horn Fuse.

Is the fuse open?

Yes

- Replace Horn 2 and the Horn Fuse. Reinstall the original Horn Relay.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Replace Horn 1. Reinstall the original Horn Relay.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

9. CHECK (A1) B(+) CIRCUIT FOR AN OPEN




1. If not done previously, turn the ignition off, and then remove the Horn Fuse.
2. Turn the ignition on.
3. Using a 12-volt test light connected to ground, check the (A1) B(+) circuit at the Horn Fuse connector.NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.

Does the test light illuminate brightly?

Yes

- Go To 10

No

- Repair the (A1) B(+) circuit for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

10. CHECK (A950) FUSED B(+) CIRCUIT FOR AN OPEN




1. Turn the ignition off.
2. Remove the Horn Relay.
3. Reinstall the Horn Fuse.
4. Turn the ignition on.
5. Using a 12-volt test light connected to ground, check the (A950) Fused B(+) circuit at the Horn Relay connector.NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.

Does the test light illuminate brightly?

Yes

- Go To 11

No

- Replace the Integrated Power Module (IPM).
- Perform the BODY VERIFICATION TEST. Body Verification Test.

11. CHECK FOR AN OPEN HORN RELAY
1. Turn the ignition off.
2. Install a known good relay in place of the Horn Relay.
3. Using a scan tool, erase DTCs.
4. Operate the Horn Switch several times.
5. Cycle the ignition from on to off three times and leave on.
6. Using a scan tool, read DTCs.

Does the scan tool display the same DTC?

Yes

- Go To 12

No

- Replace the original Horn Relay.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

12. CHECK (X4) HORN RELAY CONTROL CIRCUIT FOR A SHORT TO GROUND




1. Turn the ignition off.
2. Remove the replacement Horn Relay.
3. Disconnect the FCM from the Front Control Module IPM 49-way connector.
4. Measure the resistance of the (X4) Horn Relay Control circuit between ground and the Horn Relay connector.

Is the resistance below 10K Ohms?

Yes

- Replace the Integrated Power Module (IPM).
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 13

13. CHECK (X4) HORN RELAY CONTROL CIRCUIT FOR AN OPEN




1. Measure the resistance of the (X4) Horn Relay Control circuit between the Relay connector and the Front Control Module IPM 49-way connector.

Is the resistance below 5.0 Ohms?

Yes

- Replace the Front Control Module (FCM).
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Replace the Integrated Power Module (IPM).
- Perform the BODY VERIFICATION TEST. Body Verification Test.