Dodge Ram Truck 1500-2500-3500. Manual — part 283

BATTERY VOLTAGE OPEN (FCM) (CONTINUED)

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
With the ignition on.

•

Set Condition:
The FCM detects a low voltage condition.

Possible Causes

POWER DISTRIBUTION CENTER

FRONT CONTROL MODULE

Diagnostic Test

1.

CHECK FOR AN ACTIVE DTC

Turn the ignition on.

With the DRB, erase the FCM DTC’s.

Turn the ignition off then turn the ignition on and wait approximately 1 minute.

With the DRB, read the FCM DTC’s.

Did this DTC reset?

Yes

>> Go To 2

No

>> The condition that set this DTC is no longer present. Using the wiring diagram/schematic as a guide,

inspect the wiring for chafed, pierced, pinched, and partially broken wires and the wiring harness con-
nectors for broken, bent, pushed out, and corroded terminals.

2.

CHECK THE FUSED B+ CIRCUIT

Turn the ignition off.

Remove the FCM from the IPM.

Using a 12-volt test light connected to ground, probe the Fused B+ cir-
cuit (cavity 10).

Is the test light illuminated?

Yes

>> Replace the Front Control Module in accordance with the

service information.

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

No

>> Replace the Power Distribution Center in accordance with

the service information.

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

8E - 4

ELECTRONIC CONTROL MODULES - ELECTRICAL DIAGNOSTICS

DR/DH

BATTERY 1 VOLTAGE OPEN (FCM)

DR/DH

ELECTRONIC CONTROL MODULES - ELECTRICAL DIAGNOSTICS

8E - 5

BATTERY 1 VOLTAGE OPEN (FCM) (CONTINUED)

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
With the ignition on.

•

Set Condition:
The FCM detects low voltage on battery input 1.

Possible Causes

FUSE #13

POWER DISTRIBUTION CENTER

FRONT CONTROL MODULE

Diagnostic Test

1.

CHECK FOR AN ACTIVE DTC

Turn the ignition on.

With the DRB, erase the FCM DTC’s.

Turn the ignition off then turn the ignition on and wait approximately 1 minute.

With the DRB, read the FCM DTC’s.

Did this DTC reset?

Yes

>> Go To 2

No

>> The condition that set this DTC is no longer present. Using the wiring diagram/schematic as a guide,

inspect the wiring for chafed, pierced, pinched, and partially broken wires and the wiring harness con-
nectors for broken, bent, pushed out, and corroded terminals.

2.

CHECK FUSE #13

Turn the ignition off.

Check fuse #13 in the IPM.

Is the fuse open?

Yes

>> Replace the fuse and check for a possible intermittent short to ground condition.

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

No

>> Go To 3

8E - 6

ELECTRONIC CONTROL MODULES - ELECTRICAL DIAGNOSTICS

DR/DH

BATTERY 1 VOLTAGE OPEN (FCM) (CONTINUED)

3.

CHECK THE FUSED B+ CIRCUITS

Remove the FCM from the IPM.

NOTE: Ensure fuse #13 is installed in the IPM.
Using a 12-volt test light connected to ground, probe both Fused B+
circuits (cavities 3 and 4).

Is the test light illuminated for both circuits?

Yes

>> Replace the Front Control Module in accordance with the

service information.

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

No

>> Replace the Power Distribution Center in accordance with

the service information.

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

DR/DH

ELECTRONIC CONTROL MODULES - ELECTRICAL DIAGNOSTICS

8E - 7