Chrysler PT Cruiser 2001 Service Manual Supplement page 2772

COMMUNICATION
*NO RESPONSE FROM TCM —
TEST
7 Turn ignition off to the lock position.
Disconnect the TCM harness connector.
Note: Check connectors - Clean/repair as necessary.
Connect the ground clip of a test light to a known good 12 volt source on the vehicle
such as the positive battery post.
Probe all ground circuit(s) in the TCM connector with the test light.
Note: The light must illuminate brightly, if it does not light, or lights dimly,
the circuit must be repaired. If there is any doubt, compare the brightness
when testing the circuit, to the brightness when connected directly to the
battery.
Does the light illuminate brightly at all ground circuits?
Yes → Go To 8
No
8 NOTE: Ensure there is PCI bus communication with other modules. If not,
refer to the PCI Bus Communication Failure symptom and repair as
necessary.
Turn ignition off to the lock position.
Disconnect the TCM 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.
Select DRB Standalone.
Select lab scope.
Select Live.
Select 12 volt square wave.
Select 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 chassis ground. Connect the Red lead to the PCI Bus circuit
in the TCM connector.
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
9 Turn the ignition off.
Disconnect the Transmission Control Module harness connector.
Disconnect the DRB from the Data Link Connector.
Measure the resistance of the SCI Transmit circuit between the TCM connector and
the Data Link Connector.
Is the resistance below 5.0 ohms?
Yes → Go To 10
No
ACTION
→ Repair the Ground circuit(s) as necessary.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
Go To 9
Repair the PCI Bus circuit for an open.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
→ Repair the SCI Transmit circuit for an open.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
Continued
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APPLICABILITY
All
All
All