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Chrysler Repair/No data link connection: '01 PT


QUESTION: Tried to get my 2001 PT (auto) smog checked and California law now ONLY allows using the OBD scan and they said it won't communicate.   The car runs fine, has always passed before and the dash diagnostics function fine.   Is there a fuse or a box between the data link cable and the PCM (ECU)?   Any ideas for repair?

ANSWER: Hi Mike,
There are 8 wires on the connector of which three go to the PCM: pink on pin 7 goes to pin 65 on plug 2, and light green on pin 6 goes to pin 75. First check that you show 12v on pin 16 as that is needed to power up the code reader. It is powered by fuse 13 in the power box under the hood. Pin 2 violet/yellow also is connected to pin 59. These connections are specific to the 2.0 and 2.4L models.
Pin 4 and 5 should be grounded.

[an error occurred while processing this directive]---------- FOLLOW-UP ----------

QUESTION: Pins 4 and 5 show a solid ground and pin 16 to pin 4 shows B+.   So I just have to insure continuity for DTL pins 7 to PCM 65, DTL 6 to PCM 75 and DTL 2 to PCM 59... I would normally short one end to chassis ground and check the end for continuity then remove the ground and confirm an open... sound right?   And if that checks it confirms a PCM problem?

ANSWER: If the wire were already shorted to ground, then you might overlook that, so check that point before shorting one end to check for continuity. Ideally check continuity directly by jumping a wire from the obd plug's pin to the engine compartment so you can then check continuity between it and the pin of the plug at the pcm. If the PCM were bad then a fault code readout should show such a code if you can get a readout.

---------- FOLLOW-UP ----------

pins 4 and 5 good ground.
pin 6 shows continuity to PCM p2-75
pin 7 shows continuity to PCM p2-65
pin 2 shows continuity to PCM p2-59
pin 16 shows good B+
Guess I have to get a new (refurbished) PCM???????

Try get a trouble code:
Turn the ignition key: "on-off-on-off-on and leave-on" doing that in 5 seconds or less elapsed time. Then watch the odometer window to see if the mileage reading is replaced by a 4-digit number preceded by a P or by the word "done". Let me know what you find.
Also a nationwide auto parts store such as Autozone may do it free with a code reader. There is a code for a faulty pcm so that should show up if you need one.

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Roland Finston


Get a Free Fast answer to your repair question about a Chrysler/Dodge/Plymouth car, minivan, SUV, or truck. Problems with electronically controlled engines and transmissions as well as body wiring problems are my specialty. This free troubleshoot advice forum helps you diagnose faults, minimize repair costs or do-it-yourself.

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