Chrysler PT Cruiser 2001 Service Manual Supplement page 2501

*NO RESPONSE FROM PCM (PCI BUS) —
TEST
4 Turn the ignition off.
Disconnect the Powertrain Control Module harness connector.
Turn the ignition on.
Use a 12 volt test light in the following step.
With the 12V test light connected to ground, probe the Fused Ignition Switch Output
circuit in the PCM Connector.
Is the test light illuminated and bright?
Yes → Go To 5
No
5 With the DRB read PCM Diagnostic Trouble Codes. This is to ensure power and
grounds to the PCM are operational.
Note: If the DRB will not read PCM DTC's, follow the NO RESPONSE TO
PCM (SCI only) symptom path, if vehicle will start. For NO START Condi-
tions follow symptom NO RESPONSE in Starting category .
Turn the ignition off.
Disconnect the Powertrain Control Module harness connectors.
Connect the DRBIII to the Data Link 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.
Select DRB Standalone.
Select lab scope.
Select Live.
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 PCM ground. Connect the Red lead to the PCM PCI
Bus circuit.
Turn the ignition on.
Observe the voltage display on the DRB Lab Scope.
What is the voltage display on the scope?
Pulse from 0 to approximately 7.5 volts
Steady 0 volts
6 The Powertrain Control Module has an internal open PCI Bus and must be replaced.
If there are no possible causes remaining, view repair.
Repair
ACTION
→ Repair the Fused Ignition Switch Output circuit for an open.
Perform POWERTRAIN VERIFICATION TEST VER - 1.
Go To 6
Repair the PCI Bus circuit for an open.
Perform POWERTRAIN VERIFICATION TEST VER - 1.
Replace the Powertrain Control Module.
Perform POWERTRAIN VERIFICATION TEST VER - 1.
Continued
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