B2371

B2371-HORN CONTROL CIRCUIT OVERCURRENT-TIPM





For a complete wiring diagram Consult Diagrams/Electrical.

- When Monitored:
With the ignition on. Battery voltage greater than 10.4 volts.

- Set Condition:
An overcurrent condition in the (X21)/(X22) Horn Control Output circuit.





Diagnostic Test

1. CHECK FOR ACTIVE DTC B2371 HORN CONTROL CIRCUIT OVERCURRENT
Turn the ignition on.
With the scan tool, record and erase DTC's.
Operate the Horn Switch several times.
With the scan tool, read DTC's.
Does the scan tool display active DTC B2371-HORN CONTROL CIRCUIT OVERCURRENT?

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.

2. VISUAL AND PHYSICAL CONNECTOR AND TERMINAL INSPECTION
Turn the ignition off.
Inspect the following connector terminal condition. Check for signs of corrosion build up or damage that would compromise the terminal to controller pin connector.

NOTE: Make sure that all in-line connectors are inspected for corrosion and/or damage.

Disconnect the Horn connectors.
Disconnect the C11 TIPM harness connector.
Visually inspect the wiring harness. Look for any chafed, pierced, pinched or partially broken wires hidden in the wire insulation.
Were any of the above conditions found?

Yes

- Repair or replace as necessary.
- Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go to 3

3. (X21)/(X22) HORN CONTROL OUTPUT CIRCUIT HIGH RESISTANCE




With a jumper wire, connect one end to the (X21) Horn Control Output circuit at the Horn supply connector and the other to a clean chassis ground.
Using a 12-volt test light to battery voltage, probe the (X21) Control Output circuit in the C11 TIPM harness connector.
With a jumper wire, connect one end to the (X22) Horn Control Output circuit at the Horn connector and the other to a clean chassis ground.
Using a 12-volt test light to battery voltage, probe the (X22) Control Output circuit in the C11 TIPM harness connector.

NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.

Does the test light illuminate brightly?

Yes

- Go to 4

No

- Repair the excessive resistance in the Horn Control Output circuit.
- Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test

4. CHECKING HORN OPERATION
Turn the ignition off.
Disconnect the horns supply connectors if not disconnected.
Connect the horns ground connectors if disconnected.
Momentarily jumper 12-volts to the horn(s).
Did the horn(s) operate properly?

Yes

- Go to 6

No

- Go to 5

5. HORN GROUND CIRCUIT OPEN
Disconnect the Horns ground connectors.
Using a 12-volt test light connected to 12-volts, probe the (Z920) ground circuit at the horn connectors.
Does the test light illuminate brightly?

Yes

- Replace the Horn(s) as necessary.
- Perform the BODY VERIFICATION TEST - VER 1.Body Verification Test

No

- Repair the open or excessive resistance in the horn(s) ground circuit.
- Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test.

6. TOTALLY INTEGRATED POWER MODULE
NOTE: Before continuing, check the TIPM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Using the schematics as a guide, inspect the wire harness and connectors.
Pay particular attention to all Power and Ground circuits.
Were any problems found?

Yes

- Repair as necessary.
- Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test.

No

- Replace the Totally Integrated Power Module.
- Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test.