Dodge Ram Truck 1500-2500-3500. Manual — part 1820

4WD HI INDICATOR OPEN

21 - 1212

TRANSFER CASE - ELECTRICAL DIAGNOSTICS (ETC)

DR/DH

4WD HI INDICATOR OPEN (CONTINUED)

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
Continuously with the ignition on.

•

Set Condition:
The Transfer Case Control Module detects an open circuit or high voltage on the (G91) 4WD High Indicator
circuit.

Possible Causes

INTERMITTENT 4WD HI INDICATOR OPEN

(G91) 4WD HIGH INDICATOR CIRCUIT OPEN

(G91) 4WD HIGH INDICATOR CIRCUIT SHORT TO VOLTAGE

(F21) FUSED IGNITION SWITCH OUTPUT CIRCUIT OPEN

TRANSFER CASE SELECTOR SWITCH

TRANSFER CASE CONTROL MODULE

1.

4WD HI INDICATOR OPEN DTC IS PRESENT

With the DRBIII

T

, read Transfer Case DTCs. Record all DTC information.

With the DRBIII

T

, erase Transfer Case DTCs.

Start the engine and move the Transfer Case Selector Switch to each position.

With the DRBIII

T

, read Transfer Case DTCs.

Does the DRBIII

T

display 4WD HI INDICATOR OPEN?

Yes

>> Go To 2

No

>> Go To 7

2.

(G91) 4WD HIGH INDICATOR CIRCUIT OPEN

Turn the ignition off to the lock position.

Disconnect the Transfer Case Control Module C1 harness connector.

Disconnect the Transfer Case Selector Switch harness connector.

NOTE: Note: Check connectors - Clean/repair as necessary.
Measure the resistance of the (G91) 4WD High Indicator circuit from
the Transfer Case Control Module C1 harness connector to the Trans-
fer Case Selector Switch harness connector.

Is the resistance above 5.0 ohms?

Yes

>> Repair the (G91) 4WD High Indicator circuit for an open.

Perform TRANSFER CASE VERIFICATION TEST. (Refer
to 21 - TRANSMISSION/TRANSAXLE/TRANSFER CASE
- DIAGNOSIS AND TESTING)

No

>> Go To 3

DR/DH

TRANSFER CASE - ELECTRICAL DIAGNOSTICS (ETC)

21 - 1213

4WD HI INDICATOR OPEN (CONTINUED)

3.

(G91) 4WD HIGH INDICATOR CIRCUIT SHORT TO VOLTAGE

Ignition on, engine not running.

Measure the voltage of the (G91) 4WD High Indicator circuit.

Is the voltage above 0.5 volt?

Yes

>> Repair the (G91) 4WD High Indicator circuit for a short to

voltage.

Perform TRANSFER CASE VERIFICATION TEST. (Refer
to 21 - TRANSMISSION/TRANSAXLE/TRANSFER CASE
- DIAGNOSIS AND TESTING)

No

>> Go To 4

4.

(F21) FUSED IGNITION SWITCH OUTPUT CIRCUIT OPEN

Using a 12-volt test light connected to ground, check the (F21) Fused
Ignition Switch Output circuit.

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 5

No

>> Repair the (F21) Fused Ignition Switch Output circuit for

an open circuit or for high resistance. If the fuse is open
make sure to check for a short to ground and repair as
necessary.

Perform TRANSFER CASE VERIFICATION TEST. (Refer
to 21 - TRANSMISSION/TRANSAXLE/TRANSFER CASE
- DIAGNOSIS AND TESTING)

21 - 1214

TRANSFER CASE - ELECTRICAL DIAGNOSTICS (ETC)

DR/DH

4WD HI INDICATOR OPEN (CONTINUED)

5.

TRANSFER CASE SELECTOR SWITCH

Turn the ignition off to the lock position.

Connect the Transfer Case Control Module C1 harness connector.

Ignition on, engine not running.

With the DRBIII

T

, actuate the 4HI LED.

With a 12–volt test light connected to B+, check the (G91) 4WD High
Indicator circuit in the Transfer Case Selector Switch harness connec-
tor.

Does the test light illuminate when the circuit is actuated?

Yes

>> Replace the Transfer Case Selector Switch in accordance

with the Service Information.

Perform TRANSFER CASE VERIFICATION TEST. (Refer
to 21 - TRANSMISSION/TRANSAXLE/TRANSFER CASE
- DIAGNOSIS AND TESTING)

No

>> Go To 6

6.

TRANSFER CASE CONTROL MODULE

Using the wiring diagram as a guide, inspect the wiring and connectors relative to this DTC. Inspect all power and
ground circuits. Repair as necessary.

If there are no other possible causes remaining, view repair.

Repair

Replace the Transfer Case Control Module in accordance with the Service Information.

Perform TRANSFER CASE VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/
TRANSFER CASE - DIAGNOSIS AND TESTING)

7.

INTERMITTENT WIRING AND CONNECTORS

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

Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.

Wiggle test the wiring harness and connectors while checking for shorted and open circuits.

Using the DRBIII

T

, monitor the data related to this circuit while performing the wiggle test. Look for the data to

change or for the DTC to reset.

Were there any problems found?

Yes

>> Repair as necessary.

Perform TRANSFER CASE VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/
TRANSFER CASE - DIAGNOSIS AND TESTING)

No

>> Test Complete.

DR/DH

TRANSFER CASE - ELECTRICAL DIAGNOSTICS (ETC)

21 - 1215