Chrysler Voyager. Manual — part 236

Symptom:

*NO RESPONSE FROM ECM (PCI BUS) - DIESEL ONLY

POSSIBLE CAUSES

ECM PCI NO RESPONSE

PCI BUS CIRCUIT OPEN

ENGINE CONTROL MODULE

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, enter Body then Body Computer.
With the DRB, enter Anti-Lock Brakes.
With the DRB, enter Body then Electro/Mechanical Cluster (MIC).
With the DRB, enter Passive Restraints then Airbag.
Were you able to establish communications with any of the modules?

All

Yes

→ Go To 2

No

→ Refer to symptom PCI Bus Communication Failure in the Com-

munications category.
Perform ROAD TEST VERIFICATION - VER-2.

2

With the DRB read ECM Diagnostic Trouble Codes. This is to ensure power and
grounds to the ECM are operational.
NOTE: If the DRB will not read ECM DTCs, follow the NO RESPONSE TO
ECM (SCI only) symptom path, if vehicle will start. For NO START Condi-
tions follow the no start symptom in the powertrain diagnostic information.
Turn the ignition off.
Disconnect the ECM harness connectors.
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. Set Probe to x10.
Press F2 again when complete.
Connect the Black lead to ground. Connect the Red lead to the PCI Bus circuit in the
ECM 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 and program the Engine Control Module in accordance

with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.

No

→ Repair the PCI Bus circuit for an open.

Perform ROAD TEST VERIFICATION - VER-2.

371

COMMUNICATION

Symptom:

*NO RESPONSE FROM ECM (SCI ONLY) - DIESEL ONLY

POSSIBLE CAUSES

CHECK ECM POWERS AND GROUNDS

CABIN HEATER ASSIST

SCI TRANSMIT CIRCUIT SHORTED TO VOLTAGE

SCI TRANSMIT CIRCUIT SHORTED TO GROUND

SCI TRANSMIT CIRCUIT OPEN

ENGINE CONTROL MODULE

TEST

ACTION

APPLICABILITY

1

Perform the symptom Checking ECM Power and Ground Circuits in the Driveability
category.
Did the vehicle pass this test?

All

Yes

→ Go To 2

No

→ Repair as necessary.

Perform ROAD TEST VERIFICATION - VER-2.

2

Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the DRB from the DLC.
Measure the resistance between ground and the SCI Transmit circuit.
Is the resistance below 5.0 ohms?

All

Yes

→ Go To 3

No

→ Go To 4

3

Turn the ignition off.
Disconnect the Cabin Heater Assist C1 harness connector.
Measure the resistance between ground and the SCI Transmit circuit.
Is the resistance below 5.0 ohms?

All

Yes

→ Repair the SCI Transmit circuit for a short to ground.

Perform ROAD TEST VERIFICATION - VER-2.

No

→ Replace the Cabin Heater Assist in accordance with the service

information.
Perform ROAD TEST VERIFICATION - VER-2.

4

Turn the ignition off.
Disconnect the DRB from the DLC.
Disconnect the ECM harness connectors.
Disconnect the Cabin Heater Assist C1 harness connector.
Turn the ignition on.
Measure the voltage of the SCI Transmit circuit at the DLC connector (cav 7).
Is the voltage above 1.0 volt?

All

Yes

→ Repair the SCI Transmit circuit for a short to voltage.

Perform ROAD TEST VERIFICATION - VER-2.

No

→ Go To 5

372

COMMUNICATION

TEST

ACTION

APPLICABILITY

5

Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the DRB from the DLC.
Measure the resistance of the SCI Transmit circuit between the ECM connector and
the DLC.
Is the resistance below 5.0 ohms?

All

Yes

→ Go To 6

No

→ Repair the SCI Transmit circuit for an open.

Perform ROAD TEST VERIFICATION - VER-2.

6

If there are no possible causes remaining, view repair.

All

Repair

Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.

373

COMMUNICATION

*NO RESPONSE FROM ECM (SCI ONLY) - DIESEL ONLY —

Continued

Symptom:

*NO RESPONSE FROM FRONT CONTROL MODULE

POSSIBLE CAUSES

ATTEMPT TO COMMUNICATE WITH ANOTHER MODULE

OPEN GROUND CIRCUIT(S)

OPEN PCI BUS CIRCUIT

FRONT CONTROL MODULE

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.
With the DRB, attempt to communicate with the Body Control Module (BCM).
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.
Remove the Front Control Module from the IPM.
Using a 12-volt test light connected to 12-volts, probe both Ground circuits.
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.

374

COMMUNICATION