Dodge Ram Truck 1500-2500-3500. Manual — part 373

PCI BUS INTERNAL FAILURE

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
Continuously.

•

Set Condition:
The Instrument Cluster fails the loopback test on the PCI Bus.

Possible Causes

INSTRUMENT CLUSTER

Diagnostic Test

1.

INSTRUMENT CLUSTER

NOTE: If this is an active DTC, answer yes to the question.
With the DRBIII

T

, erase DTCs.

Cycle the ignition and wait approximately 1 minute.

With the DRBIII

T

, read DTCs.

Did this DTC reset?

Yes

>> Replace the Instrument Cluster in accordance with the Service Information.

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

No

>> Test Complete.

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INSTRUMENT CLUSTER - ELECTRICAL DIAGNOSTICS

DR/DH

PCM MESSAGES NOT RECEIVED

DR/DH

INSTRUMENT CLUSTER - ELECTRICAL DIAGNOSTICS

8J - 53

PCM MESSAGES NOT RECEIVED (CONTINUED)

For the Instrument Cluster circuit diagram (Refer to 8 - ELECTRICAL/INSTRUMENT CLUSTER - SCHEMATICS
AND DIAGRAMS).

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
With the ignition on.

•

Set Condition:
The MIC does not receive any messages from the PCM for at least 5 seconds.

Possible Causes

(D25) PCI BUS CIRCUIT OPEN

POWERTRAIN CONTROL MODULE

1.

PCM MESSAGES NOT RECEIVED

Turn the ignition on.

NOTE: To proceed in this test, the DTC must be active.
With the DRB, enter SYSTEM MONITORS then J1850 MODULE SCAN.

Is the PCM active on the BUS?

Yes

>> Check the condition of the J1850 Bus circuit wiring. Erase DTC, if DTC resets replace the Instrument

Cluster in accordance with the service information.

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

No

>> Go To 2

2.

ATTEMPT TO COMMUNICATE WITH THE PCM

Turn the ignition on.

With the DRB, attempt to communicate with the PCM.

Was the DRB able to communicate with the PCM?

Yes

>> Go To 3

No

>> Refer to the communication category and perform the appropriate symptom.

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

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INSTRUMENT CLUSTER - ELECTRICAL DIAGNOSTICS

DR/DH

PCM MESSAGES NOT RECEIVED (CONTINUED)

3.

CHECK THE (D25) PCI BUS CIRCUIT FOR AN OPEN

Turn the ignition off.

Disconnect the PCM harness connector.

CAUTION: If NGC, DO NOT PROBE THE PCM HARNESS CON-
NECTORS. PROBING THE PCM HARNESS CONNECTORS WILL
DAMAGE THE PCM TERMINALS RESULTING IN POOR TERMINAL
TO PIN CONNECTION. INSTALL MILLER SPECIAL TOOL #8815 TO
PERFORM DIAGNOSIS.
Disconnect the DRBIII

T

from the DLC.

Measure the resistance of the (D25) PCI Bus circuit between the PCM
connector (from special tool #8815 if NGC) and the DLC.

Is the resistance below 5.0 ohms?

Yes

>> Replace and program the Powertrain Control Module in

accordance with the service information.

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

No

>> Repair the (D25) PCI Bus circuit for an open.

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

DR/DH

INSTRUMENT CLUSTER - ELECTRICAL DIAGNOSTICS

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