Pinpoint Tests OA: The Hill Descent Control System Is Inoperative Or Cannot Be Disabled
WARNING: This page is about a different car, the 2018 Lincoln MKC. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.
CONNECTOR PIN REFERENCE (HARNESS SIDE)
| Circuit | Pin |
- OA1: CHECK FOR ABS MODULE DTCS
- Ignition ON, engine OFF.
- Carry out the ABS self-test.
- Are there any "lost communication" or "invalid data" DTCs other than U0401:86 present in the ABS module?
Yes No DIAGNOSE all other ABS module "lost communication" and "invalid data" DTCs before diagnosing DTC U0401:86. REFER to the ABS module DTC Chart. Go to OA6.
- OA2: CHECK IF THE ATCM COMMUNICATES ON THE NETWORK
- Press the Read Vehicle Information button to view the results of the modules communicating on the network.
- Retrieve the continuous memory DTCs.
- Does the ATCM pass the Network Test?
Yes No Go to OA3. REFER to Module Communications Network to diagnose the ATCM not responding to the scan tool.
- OA3: CHECK FOR ATCM DTCS
- Carry out the ATCM self-test.
- Are any DTCs present?
Yes No REFER to the Four Wheel Drive Systems . Go to OA4.
- OA4: VERIFY ALL WIRING CONNECTIONS ABS)
- Ignition OFF.
- Disconnect the ABS and the BCM C2280A electrical connectors.
- Disconnect all in-line electrical connectors between the ATCM and the BCM.
- Using a good light source, inspect all disconnected electrical connectors for the following:
- corrosion - install new connector or terminal and clean the module pins
- damaged or bent pins - install new terminals or pins
- pushed-out pins - install new pins as necessary
- spread terminals - install new terminals as necessary
- Are the connectors free of corrosion, damaged pins, bent pins, pushed-out pins and spread terminals?
Yes No Go to OA5. REPAIR the affected connectors or terminals. REFER to OEM Connector Repair Procedures .
- OA5: CHECK FOR CORRECT ATCM OPERATION
- Connect all in-line electrical connectors between the ATCM and the BCM. Make sure the connectors seat and latch correctly.
- Connect the ABS and the BCM C2280A electrical connectors. Make sure the connectors seat and latch correctly.
- Operate the system and determine if the concern is still present.
- Is the concern is still present?
Yes No CHECK OASIS for any applicable TSBs. If a TSB exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions. If no TSBs address this concern, INSTALL a new ATCM. REFER to Four Wheel Drive Systems . The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.
- OA6: CHECK FOR IPC DTCS
- Carry out the IPC self-test.
- Are there any DTCs in the IPC?
Yes No DIAGNOSE all IPC DTCs before diagnosing DTC U0401:86. REFER to Information Center - Instrumentation, Message Center And Warning Chimes . Go to OA7.
- OA7: CHECK THE HILL DESCENT CONTROL SWITCH
- Ignition OFF.
- Press and hold the Hill Descent Control switch while taking the measurement.
- Measure the resistance between:
(+) CSS Connector, Component Side (-) CSS Connector, Component Side HDC GND - Measure the resistance between:
(+) Hazard Switch Connector, Component Side (-) Hazard Switch Connector, Component Side HDC GND - Release the Hill Descent Control switch and take another measurement.
- Measure the resistance between:
(+) CSS Connector, Component Side (-) CSS Connector, Component Side HDC GND - Measure the resistance between:
(+) Hazard Switch Connector, Component Side (-) Hazard Switch Connector, Component Side HDC GND - Is the resistance less than 3 ohms with the switch pressed and greater than 10, 000 ohms with the switch released?
Yes No Go to OA8. INSTALL a new Hazard switch.
INSTALL a new hazard flasher switch (the hill descent control switch is part of the hazard switch assembly).
REFER to Exterior Lighting System .
- OA8: CHECK THE HILL DESCENT CONTROL SWITCH GROUND CIRCUIT FOR AN OPEN
- Measure the resistance between:
(+) CSS Connector, Harness Side (-) GND Ground - Measure the resistance between:
(+) Hazard Switch Connector, Harness Side (-) GND Ground - Is the resistance less than 3 ohms?
Yes No Go to OA9. REPAIR the circuit.
- Measure the resistance between:
- OA9: CHECK THE HILL DESCENT CONTROL SWITCH SIGNAL CIRCUIT FOR AN OPEN
- IC connector disconnected. (C220)
- Measure the resistance between:
(+) CSS Connector, Harness Side (-) IC (C220) Connector, Harness Side HDC HDC - Measure the resistance between:
(+) Hazard Switch Connector, Harness Side (-) IC (C220) Connector, Harness Side HDC HDC - Is the resistance less than 3 ohms?
Yes No Go to OA10. REPAIR the circuit.
- OA10: CHECK THE HILL DESCENT CONTROL SWITCH SIGNAL CIRCUIT FOR A SHORT TO GROUND
- Measure the resistance between:
(+) CSS Connector, Harness Side (-) HDC Ground - Measure the resistance between:
(+) Hazard Switch Connector, Harness Side (-) HDC Ground - Is the resistance greater than 10, 000 ohms?
Yes No Go to OA11. REPAIR the circuit.
- Measure the resistance between:
- OA11: VERIFY ALL WIRING CONNECTIONS
- Ignition OFF.
- Using a good light source, inspect all disconnected electrical connectors for the following:
- corrosion - install new connector or terminal and clean the module pins
- damaged or bent pins - install new terminals or pins
- pushed-out pins - install new pins as necessary
- spread terminals - install new terminals as necessary
- Are the connectors free of corrosion, damaged pins, bent pins, pushed-out pins and spread terminals?
Yes No Go to OA12. REPAIR the affected connectors or terminals.
REFER to OEM Connector Repair Procedures .
- OA12: CHECK FOR CORRECT IPC OPERATION
- IC connector connected. (C220) Make sure the connector seats and latches correctly.
- Operate the system and determine if the concern is still present.
- Is the concern is still present?
Yes No INSTALL a new IC.
CHECK OASIS for any applicable TSBs. If a TSB exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions. If no TSBs address this concern, INSTALL a new IPC. REFER to Information Center - Instrumentation, Message Center And Warning Chimes .
ORDER a replacement IPC and INCLUDE the RVC form.
If this is a Ford repair, INCLUDE the RVC on the warranty claim form.
When complete, SELECT the "X" in the top right corner to CLOSE this procedure.The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.