Jeep Wrangler TJ. Manual — part 29

Symptom:

*NO RESPONSE FROM RADIO

POSSIBLE CAUSES

NO RESPONSE FROM RADIO

OPEN FUSED IGNITION SWITCH OUTPUT CIRCUIT

OPEN FUSED B+ CIRCUIT

RADIO GROUND CIRCUIT OPEN

OPEN PCI BUS CIRCUIT

RADIO

TEST

ACTION

APPLICABILITY

1

Turn the ignition on.
Note: As soon as one or more module communicates with the DRB, answer
the question.
With the DRB, attempt to communicate with the Airbag Control Module (ACM).
With the DRB, attempt to communicate with the Instrument Cluster (MIC).
Was the DRB able to I/D or establish communications with either of the modules?

All

Yes

→ Go To 2

No

→ Refer to the Communications category and perform the symptom

PCI Bus Communication Failure.
Perform BODY VERIFICATION TEST - VER 1.

2

Turn the ignition off.
Disconnect the Radio 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 3

No

→ Check Fuse Block fuse for an open. If ok, repair the Fused Ignition

Switch Output circuit for an open or short. Refer to the wiring
diagrams located in the Service Information.
Perform BODY VERIFICATION TEST - VER 1.

3

Turn the ignition off.
Disconnect the Radio harness connector.
Using a 12-volt test light connected to ground, probe each Fused B+ circuit.
Is the test light illuminated for each circuit?

All

Yes

→ Go To 4

No

→ Repair the Fused B+ circuit for an open or short. Refer to the

wiring diagrams located in the Service Information.
Perform BODY VERIFICATION TEST - VER 1.

113

COMMUNICATION

TEST

ACTION

APPLICABILITY

4

Turn the ignition off.
Disconnect the Radio harness connector.
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 5

No

→ Repair the ground circuit for an open.

Perform BODY VERIFICATION TEST - VER 1.

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 Radio 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 Radio 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

→ Go To 6

No

→ Repair the PCI Bus circuit for an open.

Perform BODY VERIFICATION TEST - VER 1.

6

If there are no possible causes remaining, view repair.

All

Repair

Replace the Radio.
Perform BODY VERIFICATION TEST - VER 1.

114

COMMUNICATION

*NO RESPONSE FROM RADIO —

Continued

Symptom:

*NO RESPONSE FROM SENTRY KEY IMMOBILIZER MODULE

POSSIBLE CAUSES

ATTEMPT TO COMMUNICATE WITH THE INSTRUMENT CLUSTER

GROUND CIRCUIT OPEN

FUSED IGNITION SWITCH OUTPUT CIRCUIT OPEN

FUSED B(+) CIRCUIT OPEN

OPEN PCI BUS CIRCUIT

SENTRY KEY IMMOBILIZER MODULE

TEST

ACTION

APPLICABILITY

1

Turn the ignition on.
With the DRB, enter Body then Electro/Mech 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 SKIS VERIFICATION.

2

Turn the ignition off.
Disconnect the SKIM 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 SKIS VERIFICATION.

3

Turn the ignition off.
Disconnect the SKIM 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 SKIS VERIFICATION.

4

Turn the ignition off.
Disconnect the SKIM harness connector.
Using a 12-volt test light connected to ground, probe the Fused B(+) circuit.
Is the test light illuminated?

All

Yes

→ Go To 5

No

→ Check the Fuse in the Fuse Block for an open. Refer to the wiring

diagrams. If OK, repair the Fused B+ circuit for an open.
Perform SKIS VERIFICATION.

115

COMMUNICATION

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 SKIM 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 SKIM 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

→ Go To 6

No

→ Repair the PCI Bus circuit for an open.

Perform SKIS VERIFICATION.

6

If there are no possible causes remaining, view repair.

All

Repair

Replace and program the Sentry Key Immobilizer Module in
accordance with the Service Information.
Perform SKIS VERIFICATION.

116

COMMUNICATION

*NO RESPONSE FROM SENTRY KEY IMMOBILIZER MODULE —

Continued