Dodge Ram Truck 1500-2500-3500. Manual — part 1828

MISSING ENGINE RPM INPUT

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TRANSFER CASE - ELECTRICAL DIAGNOSTICS (ETC)

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MISSING ENGINE RPM INPUT (CONTINUED)

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
Continuously with the ignition on.

•

Set Condition:
The Transfer Case Control Module receives no Engine RPM bus message for 5 seconds.

Possible Causes

PCM COMMUNICATION DTC PRESENT

INTERMITTENT MISSING ENGINE RPM INPUT DTC

TRANSFER CASE CONTROL MODULE

1.

COMMUNICATION DTC PRESENT IN PCM

Ignition on, engine not running.

With the DRBIII

T

under Engine, read DTCs.

Are there any Communication DTCs present in the PCM?

Yes

>> Refer to the Communication category and perform the appropriate diagnostic procedure.

Perform TRANSFER CASE VERIFICATION TEST.

No

>> Go To 2

2.

MISSING ENGINE RPM INPUT DTC 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 allow it to idle for at least 10 seconds.

With the DRBIII

T

, read Transfer Case DTCs.

Does the DRBIII

T

display MISSING ENGINE RPM INPUT?

Yes

>> Go To 3

No

>> Go To 4

3.

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 Communication DTCs present or other possible causes remaining, view repair.

Repair

Replace the Transfer Case Control Module.

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

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TRANSFER CASE - ELECTRICAL DIAGNOSTICS (ETC)

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MISSING ENGINE RPM INPUT (CONTINUED)

4.

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.

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TRANSFER CASE - ELECTRICAL DIAGNOSTICS (ETC)

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MISSING IGNITION MESSAGE

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TRANSFER CASE - ELECTRICAL DIAGNOSTICS (ETC)

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