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Home >> Jeep >> 2003 >> TJ (CANADA) L4-2.4L >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Symptom Related Diagnostic Procedures >> Communication Problems >> No Response From PCM (PCM SCI Bus)
July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

No Response From PCM (PCM SCI Bus)

Test 1 - 3:




Test 4 - 8:




Test 4 - 11:






SYMPTOM
NO RESPONSE FROM PCM (SCI ONLY)

POSSIBLE CAUSES
- Check PCM powers and grounds
- Controller antilock brake
- SCI transmit circuit shorted to voltage
- Transmission control module
- SCI receive circuit shorted to voltage
- SCI circuits shorted together
- SCI transmit circuit shorted to ground
- SCI receive circuit shorted to ground
- SCI receive circuit open
- SCI transmit circuit open
- Powertrain control module