Pinpoint Test Y: DTC P185A:00

WARNING: This page is about a different car, the 2012 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Make sure the battery is fully charged before carrying out this pinpoint test.

Y1 CHECK FOR TCCM DTCs
NOTE: Failure to place the MSS in 2H or OFF prior to carrying out a self-test of the TCCM (to disable the ELD field coil) results in inaccurate self-test.
- Ignition ON.
- Set the MSS in 2H (ESOF or 2 speed-torque-on-demand).
- Set the MSS in OFF (2WD).
- Enter the following diagnostic mode on the scan tool: Self-Test - TCCM.
- Are any DTCs present?
  - Yes : If only DTC P185A:00 is retrieved, GO to Y2.
    For any other DTCs, REFER to the TCCM DTC Chart .
  - No : IDENTIFY the customer concern and GO to Symptom Chart - Electronic Locking Differential (ELD) System .
Y2 CHECK FOR A SHORT TO VOLTAGE ON THE LOCKER MODE SWITCH CIRCUIT
- Ignition OFF.
- Disconnect: TCCM C2371A.
- Ignition ON.
- With the MSS in 2H or OFF (depending upon vehicle option content), measure the voltage between TCCM C2371A-15, circuit CCF32 (WH/GN), harness side and ground.
  
  Fig 1: Measuring Voltage Between TCCM C2371A-15, Circuit CCF32 (WH/GN), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage present?
  - Yes : GO to Y3.
  - No : GO to Y4.
Y3 CHECK FOR A SHORT TO VOLTAGE ON THE LOCKER MODE SWITCH CIRCUIT WITH THE MSS DISCONNECTED
- Ignition OFF.
- Disconnect: MSS.
- Ignition ON.
- Measure the voltage at TCCM C2371A-15, circuit CCF32 (WH/GN), harness side and ground.
  
  Fig 2: Measuring Voltage Between TCCM C2371A-15, Circuit CCF32 (WH/GN), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage present?
  - Yes : REPAIR circuit CCF32 (WH/GN). CLEAR the DTCs. TEST the system for normal operation.
  - No : INSTALL a new MSS. REFER to Mode Select Switch (MSS) . TEST the system for normal operation.
Y4 CHECK FOR CORRECT TCCM OPERATION
- Ignition OFF.
- Disconnect and inspect all TCCM connectors.
- Repair:
  - corrosion (install new connector or terminals - clean module pins)
  - damaged or bent pins - install new terminals/pins
  - pushed-out pins - install new pins as necessary
- Connect all TCCM connectors. Make sure they are seated correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
  - Yes : INSTALL a new TCCM. REFER to Transfer Case Control Module (TCCM) . TEST the system for normal operation.
  - No : The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. ADDRESS the root cause of the connector or pin issues.