No Response From Pcm (Pcm Sci Only) - Ngc - Dodge Ram 2004 Service Manual

COMMUNICATION
Symptom:

*NO RESPONSE FROM PCM (PCM SCI ONLY) - NGC

CHECK PCM POWERS AND GROUNDS
PCM SCI TRANSMIT CIRCUIT SHORTED TO VOLTAGE
PCM SCI RECEIVE CIRCUIT SHORTED TO VOLTAGE
PCM SCI CIRCUITS SHORTED TOGETHER
PCM SCI TRANSMIT CIRCUIT SHORTED TO GROUND
PCM SCI RECEIVE CIRCUIT SHORTED TO GROUND
PCM SCI RECEIVE CIRCUIT OPEN
PCM SCI TRANSMIT CIRCUIT OPEN
POWERTRAIN CONTROL MODULE
TEST
1 Perform the symptom Checking PCM Power and Ground Circuits in the Driveability
category.
NOTE: With the DRBIII in the generic scan tool mode, attempt to commu-
nicate with the PCM.
NOTE: If the DRBIII can communicate with the PCM in the generic scan
tool mode, it may not be necessary to perform this step.
Did the vehicle pass this test?
Yes → Go To 2
→ Repair as necessary.
No
2 Turn the ignition off.
Disconnect the DRBIII from the DLC.
Disconnect the PCM harness connectors.
Turn the ignition on.
Measure the voltage of the PCM SCI Transmit circuit at the Data Link harness
connector (cav 7).
Is the voltage above 1.0 volt?
Yes → Repair the PCM SCI Transmit circuit for a short to voltage.
→ Go To 3
No
3 Turn the ignition off.
Disconnect the DRBIII from the DLC.
Disconnect the PCM harness connectors.
Turn the ignition on.
Measure the voltage of the PCM SCI Receive circuit at the Data Link harness
connector (cav 12).
Is the voltage above 1.0 volt?
Yes → Repair the PCM SCI Receive circuit for a short to voltage.
→ Go To 4
No
POSSIBLE CAUSES
ACTION
Perform (NGC) POWERTRAIN VERIFICATION TEST VER - 1.
Perform (NGC) POWERTRAIN VERIFICATION TEST VER - 1.
Perform (NGC) POWERTRAIN VERIFICATION TEST VER - 1.
284
APPLICABILITY
All
All
All