Dodge Ram Truck 1500-2500-3500. Manual — part 1843

C1401-TRANSFER CASE RANGE SELECT SWITCH CIRCUIT LOW (CONTINUED)

5.

(K77) TRANSFER CASE POSITION SENSE CIRCUIT OPEN

Measure the resistance of the (K77) Transfer Case Position Sense cir-
cuit between the Transfer Case Position Sensor harness connector
and the Final Drive Control Module harness connector.

Is the resistance greater than 5.0 ohms?

Yes

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

an open.

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

No

>> Go To 8

6.

(T525) TRANSFER CASE RETURN CIRCUIT SHORT TO GROUND

Turn the ignition off.

Disconnect the Final Drive Control Module harness connector.

Measure the resistance between the (T525) Transfer Case Return cir-
cuit and ground.

Is the resistance less than 5.0 ohms?

Yes

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

to ground.

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

No

>> Go To 7

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TRANSFER CASE - ELECTRICAL DIAGNOSTICS (POWER WAGON)

DR/DH

C1401-TRANSFER CASE RANGE SELECT SWITCH CIRCUIT LOW (CONTINUED)

7.

(T525) TRANSFER CASE RETURN CIRCUIT OPEN

Measure the resistance of the (T525) Transfer Case Return circuit
between the Transfer Case Position Sensor harness connector and
the Final Drive Control Module harness connector.

Is the resistance above 5.0 ohms?

Yes

>> Repair the (T525) Transfer Case Return circuit for an

open.

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

No

>> Go To 8

8.

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)

9.

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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C1402-TRANSFER CASE RANGE SELECT SWITCH CIRCUIT HIGH

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TRANSFER CASE - ELECTRICAL DIAGNOSTICS (POWER WAGON)

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

For a complete wiring diagram Refer to Section 8W

•

When Monitored:
With the ignition on and no system undervoltage or overvoltage condition present.

•

Set Condition:
The sensed voltage is greater than a specified voltage for a calibrated amount of time.

Possible Causes

INTERMITTENT TRANSFER CASE RANGE SELECTOR SWITCH CIRCUIT HIGH

(K77) TRANSFER CASE POSITION SENSE CIRCUIT SHORTED TO VOLTAGE

(T525) TRANSFER CASE RETURN CIRCUIT SHORTED TO VOLTAGE

TRANSFER CASE POSITION SENSOR

FINAL DRIVE CONTROL MODULE

Diagnostic Test

1.

4WD RANGE SWITCH VOLTAGE ABOVE 4.5 VOLTS

Ignition on, engine not running.

NOTE: Repair any system undervoltage or overvoltage DTCs that are set in this module before proceeding.
With the scan tool under Data Display, read the 4WD Range Switch voltage.

Is the volage above 4.5 volts?

Yes

>> Go To 2

No

>> Go to 6

2.

TRANSFER CASE POSITION SENSOR

Turn the ignition off.

Disconnect the Transfer Case Position Sensor harness connector.

Ignition on, engine not running.

With the scan tool under Data Display, read the 4WD Range Switch voltage.

Is the voltage equal to 0 volts?

Yes

>> Replace the Transfer Case Position Sensor.

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

No

>> Go to 3

DR/DH

TRANSFER CASE - ELECTRICAL DIAGNOSTICS (POWER WAGON)

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