Dodge Ram Truck 1500-2500-3500. Manual — part 1844

C1402-TRANSFER CASE RANGE SELECT SWITCH CIRCUIT HIGH (CONTINUED)

3.

(K77) TRANSFER CASE POSITION SENSE CIRCUIT SHORTED TO VOLTAGE

Turn the ignition on.

Measure the voltage of the (K77) Transfer Case Position Sense circuit.

Is the voltage above 5.5 volts?

Yes

>> Repair the (K77) Transfer Case Position Sense circuit for

a short to voltage.

Perform the FDCM VERIFICATION TEST. (Refer to 3 -
DIFFERENTIAL & DRIVELINE - DIAGNOSIS AND TEST-
ING)

No

>> Go to 4

4.

(T525) TRANSFER CASE RETURN CIRCUIT SHORTED TO VOLTAGE

Turn the ignition off.

Disconnect the Final Drive Control Module harness connector.

Turn the ignition on.

Measure the voltage of the (T525) Transfer Case Return circuit.

Is there any voltage present?

Yes

>> Repair the (T525) Transfer Case Return circuit for a short

to voltage.

Perform the FDCM VERIFICATION TEST. (Refer to 3 -
DIFFERENTIAL & DRIVELINE - DIAGNOSIS AND TEST-
ING)

No

>> Go to 5

5.

FINAL DRIVE CONTROL MODULE

Repair

Replace the Final Drive Control Module in accordance with the Service Information.

Perform the FDCM VERIFICATION TEST.

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TRANSFER CASE - ELECTRICAL DIAGNOSTICS (POWER WAGON)

DR/DH

C1402-TRANSFER CASE RANGE SELECT SWITCH CIRCUIT HIGH (CONTINUED)

6.

INTERMITTENT WIRING AND CONNECTORS

The conditions necessary to set this DTC are not present at this time.

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.

While monitoring the scan tool data relative to this circuit, wiggle test the wiring and connectors.

Look for the data to change or for the DTC to reset during the wiggle test.

While monitoring the scan tool data relative to this circuit, move the selector switch to each position several times.

Look for the data to change other than as expected or for the DTC to reset.

Were any problems found?

Yes

>> Repair as necessary.

Perform the FDCM VERIFICATION TEST. (Refer to 3 - DIFFERENTIAL & DRIVELINE - DIAGNOSIS
AND TESTING)

No

>> Test complete.

DR/DH

TRANSFER CASE - ELECTRICAL DIAGNOSTICS (POWER WAGON)

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C2100–BATTERY VOLTAGE LOW (FDCM)

For a complete wiring diagram Refer to Section 8W

•

When Monitored:
Continuously.

•

Set Condition:
The Final Drive Control Module detects that system voltage is below 9.0 volts for 60 seconds.

Possible Causes

INTERMITTENT BATTERY VOLTAGE LOW

CHARGING SYSTEM DTCS PRESENT

FINAL DRIVE CONTROL MODULE POWER CIRCUITS OPEN OR HIGH RESISTANCE

FINAL DRIVE CONTROL MODULE

Diagnostic Test

1.

CHARGING SYSTEM DTCS PRESENT

Ignition on.

With the scan tool, select View DTCs in the Powertrain Control Module.

Are there any Charging System or related voltage DTCs present?

Yes

>> Refer to the symptom list and perform any Charging System DTC diagnostic procedures before con-

tinuing with this test.

No

>> Go to 2

2.

DTC IS ACTIVE

With the scan tool, select View DTCs in the Final Drive Control Module.

Is the status Active for this DTC?

Yes

>> Go to 3

No

>> Go to 5

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TRANSFER CASE - ELECTRICAL DIAGNOSTICS (POWER WAGON)

DR/DH

C2100–BATTERY VOLTAGE LOW (FDCM) (CONTINUED)

3.

(A34) FUSED B+ CIRCUIT OPEN OR HIGH RESISTANCE

Turn the ignition off.

Disconnect the Final Drive Control Module harness connector.

Turn the ignition on.

With a 12–volt test light connected to ground, check the (A34) Fused
B+ circuit in the Final Drive Control Module harness connector.

NOTE: The test light must illuminate brightly. Compare the bright-
ness to that of a direct connection to the battery.

Does the test light illuminate brightly?

Yes

>> Go to 4

No

>> Repair the (A34) Fused B+ circuit for an open circuit or

high resistance.

Perform the FDCM VERIFICATION TEST. (Refer to 3 -
DIFFERENTIAL & DRIVELINE - DIAGNOSIS AND TEST-
ING)

4.

FINAL DRIVE CONTROL MODULE

View repair.

Repair

Replace the Final Drive Control Module in accordance with the Service information.

Perform the FDCM VERIFICATION TEST. (Refer to 3 - DIFFERENTIAL & DRIVELINE - DIAGNOSIS
AND TESTING)

5.

INTERMITTENT WIRING AND CONNECTORS

The conditions necessary to set this DTC are not present at this time.

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.

While monitoring the scan tool data relative to this circuit, wiggle test the wiring and connectors.

Look for the data to change or for the DTC to reset during the wiggle test.

Were any problems found?

Yes

>> Repair as necessary.

Perform the FDCM VERIFICATION TEST. (Refer to 3 - DIFFERENTIAL & DRIVELINE - DIAGNOSIS
AND TESTING)

No

>> Test complete.

DR/DH

TRANSFER CASE - ELECTRICAL DIAGNOSTICS (POWER WAGON)

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