Diagnostic Test

WARNING: This page is about a different car, the 2014 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

TEST FOR INTERMITTENT CONDITION
1. Turn the ignition on.
2. With the scan tool, record and erase DTCs.
3. Cycle the ignition from on to off three times.
4. Turn the ignition on and wait 10 seconds.
5. With the scan tool, read active DTCs.
  Does the scan tool display this DTC as active?
  
  Yes
  - Go To 2
  No
  - Test complete, 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.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE CAN IHS BUS CIRCUITS FOR A CONCERN WHILE DISCONNECTING THE CAN IHS BUS MODULES
NOTE:
When performing this step, turn the ignition off (wait one minute) before disconnecting any module. When the module is disconnected turn the ignition on.

NOTE:
The BCM contains pass-through circuits which are used to connect the Front and Rear CAN IHS Star Connectors.
1. While monitoring the scan tool, disconnect each CAN IHS Bus (125K) module at the CAN IHS Star Connectors (except for the BCM and DLC), one at a time.
2. Check for this DTC to become stored after disconnecting each CAN IHS Bus (125K) module the vehicle is equipped with.
  NOTE:
  If the DTC becomes stored when a particular module is disconnected, that module or related circuits are causing the DTC to set.
  
  With all the CAN IHS Bus modules disconnected at the Star Connectors (except for BCM and DLC), does the scan tool display this DTC as active?
  
  Yes
  - Go To 3
  No
  - Diagnose the wiring and connectors between the CAN IHS Star Connector and the module that when disconnected caused this DTC to become stored for damage or shorted circuits. If OK, replace the module that when disconnected caused this DTC to become stored in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE (D158) CAN IHS BUS (125K) (-) CIRCUIT FOR A SHORT TO VOLTAGE

Fig 1: Checking CAN IHS BUS (125K) (-) Circuit For A Short To Voltage
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off.
2. Disconnect the scan tool.
3. Turn the ignition on.
4. Measure the voltage between ground and the (D158) CAN IHS Bus (125K) (-) circuit.
  Is the voltage above 10.0 volts?
  
  Yes
  - Repair the short to voltage in the (D158) CAN IHS Bus (125K) (-) circuit.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 4
CHECK THE (D157) CAN IHS BUS (125K) (+) CIRCUIT FOR A SHORT TO GROUND

Fig 2: Checking CAN IHS BUS (125K) (+) Circuit For A Short To Ground
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off.
2. Measure the resistance between ground and the (D157) CAN IHS Bus (125K) (+) circuit.
  Is the resistance above 10k Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the short to ground in the (D157) CAN IHS Bus (125K) (+) circuit.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK FOR CORRECT BUS TERMINATION RESISTANCE

Fig 3: Checking For Correct BUS Termination Resistance
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off.
2. Disconnect and isolate the negative battery cable.
3. Measure the resistance between the (D157) CAN IHS Bus (125K) (+) circuit and the (D158) CAN IHS Bus (125K) (-) circuit.
  Is the resistance between 53.5 and 67 Ohms?
  
  Yes
  - Replace the Body Control Module (BCM) in accordance with the Service Information. Refer to MODULE, BODY CONTROL, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - For a resistance measurement above 67 Ohms, an open or high resistance is present in the CAN IHS Bus (125K) (+) circuit or the CAN IHS Bus (125K) (-) circuit between the Star Connectors or one of the termination resistors internal to the Star Connector is damaged. Diagnose and repair as necessary.
  - For a resistance measurement below 53.5 Ohms, a short between the CAN IHS Bus (125K) (+) circuit and the CAN IHS Bus (125K) (-) is present. Diagnose the short between the CAN IHS Bus (125K) (+) circuit and the CAN IHS Bus (125K) (-) circuit. Use the Star Connectors to isolate portions of the bus to assist in determining the location of the concern. Diagnose and repair as necessary.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .