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.

READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR THE DTC TO RETURN
1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
2. For future reference, with the scan tool, run and save a vehicle Scan Report and all related recorded data.
3. With the scan tool, erase all DTCs.
4. Turn the ignition off for a minimum of 10.0 seconds.
5. Turn the ignition on.
6. Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
7. With the scan tool, read DTCs.
  Did the DTC return?
  
  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 Brake Switch DTCs present in the BCM or ABS module?
  
  Yes
  - Perform the applicable diagnostic procedure(s).
  - Refer to DIAGNOSTIC CODE INDEX, ABS .
  - Refer to BODY CONTROL MODULE (BCM) - DIAGNOSTIC CODE INDEX .
  No
  - Go To 3
CHECK FOR AN ACTIVE CONDITION
NOTE:
Verify that the Brake Switch is adjusted properly before continuing.
1. Turn the ignition on.
2. With the scan tool, read the Brake Switch 1 state.
  NOTE:
  It may be necessary to test drive the vehicle while monitoring the switch state. An improperly adjusted switch may cause Brake Switch 1 to intermittently be applied while driving.
  
  Did Brake Switch 1 change states without applying the brakes while driving?
  
  Yes
  - Check the Brake Switch for proper adjustment. If the Brake Switch is not improperly adjusted, replace the switch in accordance with the Service Information.
  No
  - Go To 4
CHECK THE BRAKE SWITCH 2 SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the Brake Switch harness connector.
3. Turn the ignition on.
4. Measure the voltage between ground and the (B134) Brake Switch 2 Signal circuit at the Brake Switch harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (B134) Brake Switch 2 Signal circuit for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 3.2L .
  No
  - Go To 5
CHECK THE BRAKE SWITCH FOR PROPER OPERATION
1. Turn the ignition off.
2. Reconnect the Brake Switch harness connector.
3. Turn the ignition on.
4. Back probe and measure the voltage on the (B134) Brake Switch 2 Signal at the Brake Switch with the Brake Pedal PRESSED.
  NOTE:
  The Brake Switch 2 signal is normally closed and should not read voltage when the pedal is PRESSED.
  
  Is there voltage present when the Brake Pedal is PRESSED?
  
  Yes
  - Replace the Brake Switch in accordance with the Service Information. Refer to SWITCH, STOP LAMP, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 3.2L .
  No
  - Go To 6
CHECK RELATED BCM AND COMPONENT CONNECTIONS
1. Perform any Service Bulletins that apply.
2. Disconnect all BCM harness connectors.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. 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.
6. Reconnect all BCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
11. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Replace and program the Body Control Module in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 3.2L .
  No
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 3.2L .
  - Test complete.