Dodge Ram Truck 1500-2500-3500. Manual — part 399

FCM-RIGHT TRAILER RELAY OUTPUT

CIRCUIT LOW . . . . . . . . . . . . . . . . . . . . . . . . 96

FCM-RIGHT TRAILER RELAY OUTPUT

CIRCUIT OPEN . . . . . . . . . . . . . . . . . . . . . . . 98

MIC-TURN HAZARD SWITCH INPUT

CIRCUIT OPEN . . . . . . . . . . . . . . . . . . . . . . 101

MIC-TURN HAZARD SWITCH INPUT

CIRCUIT SHORTED . . . . . . . . . . . . . . . . . . . 104

LAMPS/LIGHTING - EXTERIOR - ELECTRICAL DIAGNOSTICS

DIAGNOSIS AND TESTING

8L - 2

LAMPS/LIGHTING - EXTERIOR - ELECTRICAL DIAGNOSTICS

DR/DH

FCM-FRONT FOG LAMP RELAY OUTPUT CIRCUIT HIGH

DR/DH

LAMPS/LIGHTING - EXTERIOR - ELECTRICAL DIAGNOSTICS

8L - 3

FCM-FRONT FOG LAMP RELAY OUTPUT CIRCUIT HIGH (CONTINUED)

For the Exterior Lighting system circuit diagram (Refer to 8 - ELECTRICAL/LAMPS/LIGHTING - EXTERIOR -
SCHEMATICS AND DIAGRAMS).

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
With the ignition on

•

Set Condition:
The FCM detects a HIGH condition

Possible Causes

FOG LAMP RELAY

INTEGRATED POWER MODULE

FRONT CONTROL MODULE

1.

INTERMITTENT CONDITION

Turn the ignition on.

With the DRBIII

T

, clear all FCM DTC’s.

Turn the Fog Lamps on.

With the DRBIII

T

, read the DTC information.

Does the DRBIII

T

read: Front Fog Lamp Relay

Output Circuit High?

Yes

>> Go To 2

No

>> The condition that caused the symptom is

currently not present. Inspect the related
wiring for a possible intermittent condition.
Look for any chafed, pierced,pinched, or
partially broken wires.

Perform BODY VERIFICATION TEST -
VER 1.

8L - 4

LAMPS/LIGHTING - EXTERIOR - ELECTRICAL DIAGNOSTICS

DR/DH

FCM-FRONT FOG LAMP RELAY OUTPUT CIRCUIT HIGH (CONTINUED)

2.

FOG LAMP RELAY

Turn the ignition off.

Remove and install a known good relay in place of the Fog Lamp
Relay.

Do the Fog Lamps operate normally?

Yes

>> Replace the Fog Lamp Relay.

Perform BODY VERIFICATION TEST - VER 1.

No

>> Go To 3

3.

FRONT CONTROL MODULE

Turn the ignition off.

Remove the Fog Lamp Relay from the IPM.

Remove the Front Control Module from the IPM.

Measure the voltage of the Fog Lamp Relay Control circuit and ground.

Is the voltage above 1.0 volts?

Yes

>> Replace the Integrated Power Module.

Perform BODY VERIFICATION TEST - VER 1.

No

>> Replace the Front Control Module.

Perform BODY VERIFICATION TEST - VER 1.

DR/DH

LAMPS/LIGHTING - EXTERIOR - ELECTRICAL DIAGNOSTICS

8L - 5