Diagnostic Test

WARNING: This page is about a different car, the 2020 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR AN ACTIVE DTC
NOTE:
Make sure the battery is fully charged before continuing.
1. Turn the ignition on.
2. With the scan tool, record and erase the DTCs.
3. Try to start the engine.
4. With the scan tool, read RF Hub DTCs.
  Is the DTC active?
  
  Yes
  - Go To 2
  No
  - The condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension and repair as necessary. If no problems are found, test complete.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
(A910) FUSED B+ OR (Z917) GROUND CIRCUIT OPEN
1. Turn the ignition off.
2. Disconnect the Keyless Ignition Node harness connector.
3. Connect a 12 volt test light between the (A910) Fused B+ circuit and the (Z917) Ground circuit.
  Does the test light illuminate brightly? Compare the brightness to that of a direct connection to the battery.
  
  Yes
  - Go To 3
  No
  - Test the (A910) Fused B+ and (Z917) Ground circuits to determine where the high resistance is. Repair the high resisted circuit as necessary.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
(D122) SECURITY K LINE COMMUNICATION CIRCUIT OPEN
1. Measure the voltage between ground and the (D122) Security K Line Communication circuit.
  Is the voltage between 9 - 12 volts?
  
  Yes
  - If equipped with a Keyless Ignition Node (KIN), replace it in accordance with Service Information. Refer to MODULE, KEYLESS IGNITION NODE (KIN), REMOVAL .
  - If equipped with an Ignition Node Module (IGNM), replace it in accordance with Service Information.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 4
(D122) SECURITY K LINE COMMUNICATION WIRE OPEN
1. Disconnect the Radio Frequency Hub C1 harness connector.
2. Measure the resistance of the (D122) Security K Line Communication wire between the Keyless Ignition Node harness connector and the RF Hub C1 harness connector.
  Is the resistance below 1.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the open in the (D122) Security K Line Communication wire.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
(D122) SECURITY K LINE COMMUNICATION SHORT TO GROUND
1. Measure the resistance between ground and the (D122) Security K Line Communication circuit in the KIN or IGNM harness connector.
  Is the resistance below 10K Ohms?
  
  Yes
  - Repair the short to ground in the (D122) Security K Line Communication circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Replace the Radio Frequency Hub (RF Hub) Module in accordance with the Service Information. Refer to MODULE, RADIO FREQUENCY (RF HUB), REMOVAL .
  - Perform the RADIO FREQUENCY HUB VERIFICATION TEST. Refer to RADIO FREQUENCY HUB (RF HUB) VERIFICATION TEST .