Diagnostic Test

WARNING: This page is about a different car, the 2017 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR AN ACTIVE DTC
1. Start the engine and allow it to idle.
  WARNING:
  When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.
2. With the scan tool, read DTCs and record on the repair order.
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK FOR OTHER DTCS
1. Refer to the recorded DTCs.
  Are there any system voltage or 5-Volt Reference DTCs active or pending?
  
  Yes
  - Perform the applicable diagnostic procedure(s). Refer to 2.4L - DIAGNOSTIC CODE INDEX .
  No
  - Go To 3
CHECK THE (K854) 5-VOLT SUPPLY CIRCUIT VOLTAGE
1. Turn the ignition off.
2. Disconnect the A/C Pressure Transducer harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (K854) 5-Volt Supply circuit in the A/C Pressure Transducer harness connector.
  Is the voltage above 4.8 volts?
  
  Yes
  - Go To 4
  No
  - Repair the (K854) 5-Volt Supply circuit for an open circuit or short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 2.4L .
CHECK THE (C18) A/C PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the PCM C1 harness connector.
3. Check for continuity between ground and the (C18) A/C Pressure Sensor Signal circuit at the A/C Pressure Transducer harness connector.
  Is there continuity between ground and the (C18) A/C Pressure Sensor Signal circuit?
  
  Yes
  - Repair the (C18) A/C Pressure Sensor Signal circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 2.4L .
  No
  - Go To 5
CHECK FOR THE (C18) A/C PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO THE (K914) GROUND CIRCUIT
1. Check for continuity between the (C18) A/C Pressure Sensor Signal circuit and the (K914) Ground circuit at the A/C Pressure Transducer harness connector.
  Is there continuity between the (C18) A/C Pressure Sensor Signal circuit and the (K914) Ground circuit at the A/C Pressure Transducer harness connector?
  
  Yes
  - Repair the short between (C18) A/C Pressure Sensor Signal circuit for a short to the (K914) A/C Pressure Sensor Ground circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 2.4L .
  No
  - Go To 6
CHECK THE ABILITY OF THE PCM TO READ THE A/C PRESSURE TRANSDUCER SIGNAL
1. Reconnect the PCM C1 harness connector.
2. Connect a jumper between the (K854) 5-Volt Supply circuit and the (C18) A/C Pressure Sensor Signal circuit in the A/C Pressure Transducer harness connector.
3. Turn the ignition on.
4. With the scan tool, read the AC Pressure Transducer signal voltage.
  Is the voltage above 4.8 volts with the jumper in place?
  
  Yes
  - Replace the A/C Pressure Transducer in accordance with the Service Information. Refer to TRANSDUCER, A/C PRESSURE, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 2.4L .
  No
  - Go To 7
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all PCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Check for spread terminals and verify proper terminal tension.
  Repair any conditions that are found.
5. Connect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
10. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL, 2.4L/3.2L .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 2.4L .
  No
  - The wiring or poor connection problem has been repaired.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 2.4L .