Dodge Ram Truck 1500-2500-3500. Manual — part 346

HORN RELAY CONTROL CIRCUIT OPEN

8H - 8

HORN SYSTEM - ELECRICAL DIAGNOSTICS

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HORN RELAY CONTROL CIRCUIT OPEN (CONTINUED)

For the Horn System circuit diagram (Refer to 8 - ELECTRICAL/HORN - SCHEMATICS AND DIAGRAMS)

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
With the ignition ON.

•

Set Condition:
When the Front Control Module detects a short on the Horn Relay Control circuit.

Possible Causes

INTERMITTENT DTC

FUSE #45

INTEGRATED POWER MODULE

FRONT CONTROL MODULE

Diagnostic Test

1.

HORN RELAY CONTROL CIRCUIT DTC ACTIVE

Turn the ignition on.

With the DRBIII

T

, record and erase FCM DTC’s.

With the DRBIII

T

, read FCM DTC’s.

Does the DRBIII

T

display a HORN RELAY CONTROL CIRCUIT DTC active?

Yes

>> Go To 2

No

>> Go To 4

2.

CHECK FUSE #45

Turn the ignition off.

Check fuse #45 in the IPM.

Is the fuse open?

Yes

>> Replace the fuse. Check for a short to ground in the Horn Relay Output circuit from the IPM to the

horns.

Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/FRONT CONTROL MODULE - DIAGNOSIS AND TESTING)

No

>> Go To 3

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HORN SYSTEM - ELECRICAL DIAGNOSTICS

8H - 9

HORN RELAY CONTROL CIRCUIT OPEN (CONTINUED)

3.

INTEGRATED POWER MODULE

Reinstall the fuse if previously removed.

Remove the Front Control Module from the Integrated Power Module.

NOTE: Check connectors - Clean/repair as necessary.
Turn the ignition on.

Measure the voltage of the Horn Relay Control circuit.

Is the voltage above 11.0 volts?

Yes

>> Replace the Front Control Module in accordance with the

Service Information.

Perform BODY VERIFICATION TEST - VER 1.

No

>> Replace the Integrated Power Module in accordance with

the Service Information.

Perform BODY VERIFICATION TEST - VER 1. (Refer to 8
-

ELECTRICAL/ELECTRONIC

CONTROL

MODULES/

FRONT CONTROL MODULE - DIAGNOSIS AND TEST-
ING)

4.

WIRING HARNESS INSPECTION

Turn the ignition off.

Visually inspect the related circuit connectors. Look for broken, bent, pushed out, or corroded terminals.

Refer to any Hotline letters or Technical Service Bulletins that may apply.

Were any problems found?

Yes

>> Repair as necessary.

Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/FRONT CONTROL MODULE - DIAGNOSIS AND TESTING)

No

>> Test Complete.

8H - 10

HORN SYSTEM - ELECRICAL DIAGNOSTICS

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*HORNS INOPERATIVE

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HORN SYSTEM - ELECRICAL DIAGNOSTICS

8H - 11