Dodge Ram. Manual — part 70

TEST

ACTION

APPLICABILITY

5

Note: Ensure there is PCI Bus communication with other modules on the
vehicle before proceeding. If not, refer to the symptom list from the menu
and repair as necessary.
Disconnect the Hands Free Module harness connector.
Use Scope input cable CH7058, Cable to Probe adapter CH7062, and the red and
black test probes.
Connect the scope input cable to the channel one connector on the DRB. Attach the
red and black leads and the cable to probe adapter to the scope input cable.
With the DRBIII

t select Pep Module Tools.

Select lab scope.
Select Live Data.
Select 12 volt square wave.
Press F2 for Scope.
Press F2 and use the down arrow to set voltage range to 20 volts. Press F2 again
when complete.
Connect the Black lead to the chassis ground. Connect the Red lead to the PCI Bus
circuit in the Hands Free Module connector.
Turn the ignition on.
Observe the voltage display on the DRB Lab Scope.
Does the voltage pulse from 0 to approximately 7.5 volts?

All

Yes

→ Replace the Hands Free Module in accordance with the Service

Information.
Perform BODY VERIFICATION TEST - VER 1.

No

→ Repair the PCI Bus circuit for an open.

Perform BODY VERIFICATION TEST - VER 1.

277

COMMUNICATION

*NO RESPONSE FROM HANDS FREE MODULE —

Continued

Symptom:

*NO RESPONSE FROM HVAC

POSSIBLE CAUSES

ATTEMPT TO COMMUNICATE WITH THE INSTRUMENT CLUSTER

GROUND CIRCUIT OPEN

FUSED IGNITION SWITCH OUTPUT CIRCUIT OPEN

OPEN PCI BUS CIRCUIT

A/C HEATER CONTROL

TEST

ACTION

APPLICABILITY

1

Turn the ignition on.
With the DRB, enter Body then Instrument Cluster.
Was the DRB able to I/D or communicate with the Instrument Cluster?

All

Yes

→ Go To 2

No

→ Refer to the symptom list for problems related to no communica-

tion with the Instrument Cluster.
Perform BODY VERIFICATION TEST - VER 1.

2

Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Using a 12-volt test light connected to 12-volts, probe the ground circuit.
Is the test light illuminated?

All

Yes

→ Go To 3

No

→ Repair the Ground circuit for an open.

Perform BODY VERIFICATION TEST - VER 1.

3

Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Turn the ignition on.
Using a 12-volt test light connected to ground, probe the Fused Ignition Switch
Output circuit.
Is the test light illuminated?

All

Yes

→ Go To 4

No

→ Repair the Fused Ignition Switch Output circuit for an open.

Perform BODY VERIFICATION TEST - VER 1.

278

COMMUNICATION

TEST

ACTION

APPLICABILITY

4

Note: Ensure there is PCI Bus communication with other modules on the
vehicle before proceeding. If not, refer to the symptom list from the menu
and repair as necessary.
Disconnect the A/C Heater Control C1 harness connector.
Use Scope input cable CH7058, Cable to Probe adapter CH7062, and the red and
black test probes.
Connect the scope input cable to the channel one connector on the DRB. Attach the
red and black leads and the cable to probe adapter to the scope input cable.
With the DRBIII

t select Pep Module Tools.

Select lab scope.
Select Live Data.
Select 12 volt square wave.
Press F2 for Scope.
Press F2 and use the down arrow to set voltage range to 20 volts. Press F2 again
when complete.
Connect the Black lead to the chassis ground. Connect the Red lead to the PCI Bus
circuit in the A/C Heater Control connector.
Turn the ignition on.
Observe the voltage display on the DRB Lab Scope.
Does the voltage pulse from 0 to approximately 7.5 volts?

All

Yes

→ Replace the A/C Heater Control in accordance with the service

information.
Perform BODY VERIFICATION TEST - VER 1.

No

→ Repair the PCI Bus circuit for an open.

Perform BODY VERIFICATION TEST - VER 1.

279

COMMUNICATION

*NO RESPONSE FROM HVAC —

Continued

Symptom:

*NO RESPONSE FROM INSTRUMENT CLUSTER

POSSIBLE CAUSES

ATTEMPT TO COMMUNICATE WITH ANOTHER MODULE

OPEN GROUND CIRCUIT(S)

OPEN FUSED IGNITION SWITCH OUTPUT CIRCUITS

OPEN FUSED B+ CIRCUIT(S)

OPEN PCI BUS CIRCUIT

INSTRUMENT CLUSTER

TEST

ACTION

APPLICABILITY

1

Turn the ignition on.
With the DRB, attempt to communicate with the Airbag Control Module.
With the DRB, attempt to communicate with the Controller Antilock Brake (CAB)
module.
Was the DRB able to I/D or communicate with any of the modules?

All

Yes

→ Go To 2

No

→ Refer to symptom list for problems related to the PCI Bus

Communication Failure.
Perform BODY VERIFICATION TEST - VER 1.

2

Turn the ignition off.
Turn all lights off.
Disconnect the Instrument Cluster harness connectors.
Using a 12-volt test light connected to 12-volts, probe each ground circuit.
Is the test light illuminated for each circuit?

All

Yes

→ Go To 3

No

→ Repair the ground circuit(s) for an open.

Perform BODY VERIFICATION TEST - VER 1.

3

Turn the ignition off.
Disconnect the Instrument Cluster harness connectors.
Turn the ignition on.
Using a 12-volt test light connected to ground, probe each Fused Ignition Switch
Output circuit.
Is the test light illuminated for each circuit?

All

Yes

→ Go To 4

No

→ Repair the Fused Ignition Switch Output circuit for an open or

short. Refer to the wiring diagrams in the service information.
Perform BODY VERIFICATION TEST - VER 1.

280

COMMUNICATION