Pinpoint Test I: DTCS C1987/C1988: YELLOW ELECTRONIC PARKING BRAKE (EPB) FAULT WARNING INDICATOR SHORT TO BATTERY/CIRCUIT FAILURE

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I1 CHECK THE EPB SWITCH
- Disconnect: EPB Switch C3218.
- Measure the resistance between the EPB switch C3218-6, circuit 31S-CG14 (BK/GN), component side and the EPB switch C3218-7, circuit 75-CG14 (YE/GN), component side.
  
  Fig 1: Measuring Resistance Between EPB Switch C3218-6, Circuit 31S-CG14 (BK/GN), Component Side And EPB Switch C3218-7, Circuit 75-CG14 (YE/GN), Component Side
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 15 ohms
- Yes : GO to 12.
- No : INSTALL a new EPB switch. REFER to PARKING BRAKE SWITCH in this article . CLEAR the DTCs. REPEAT the self-test. RESET the EPB system. REFER to ELECTRONIC PARKING BRAKE (EPB) RESETTING in this article .
I2 CHECK CIRCUIT 31S-CG14 (BK/GN) FOR A SHORT TO VOLTAGE
- Disconnect: EPB Module C4205b.
- Measure the voltage between the EPB module C4205b-2, circuit 31S-CG14 (BK/GN), harness side and ground.
  
  Fig 2: Measuring Voltage Between EPB Module C4205B-2, Circuit 31S-CG14 (BK/GN), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is voltage present
- Yes : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test. RESET the EPB system. REFER to ELECTRONIC PARKING BRAKE (EPB) RESETTING in this article .
- No : GO to 13.
I3 CHECK CIRCUIT 31S-CG14 (BK/GN) FOR A SHORT TO GROUND
- Measure the resistance between the EPB module C405b-2, circuit 31S-CG14 (BK/GN) harness side and ground; and between the EPB switch C3218-6, circuit 31S-CG14 (BK/GN), harness side and ground.
  
  Fig 3: Measuring Resistance Between EPB Module C405b-2, Circuit 31S-CG14 Harness Side And Ground; And Between EPB Switch C3218-6, Circuit 31S-CG14, Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms
- Yes : GO to 14
- No : REPAIR the circuit. REPEAT the self-test. CLEAR the DTC(s). RESET the EPB system. REFER to ELECTRONIC PARKING BRAKE (EPB) RESETTING in this article .
I4 CHECK CIRCUIT 31S-CG14 (BK/GN) FOR AN OPEN
- Disconnect the battery. Refer to CHARGING SYSTEM - GENERAL INFORMATION .
- Measure the resistance between the EPB module C4205b-2, circuit 31S-CG14 (BK/GN), harness side and the EPB switch C3218-6, circuit 31S-CG14 (BK/GN), harness side.
  
  Fig 4: Measuring Resistance Between EPB Module C4205b-2, Circuit 31S-CG14 (BK/GN), Harness Side And EPB Switch C3218-6, Circuit 31S-CG14 (BK/GN), Harness Side
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms
- Yes : GO to 15.
- No : REPAIR the circuit. REPEAT the self-test. CLEAR the DTC(s). RESET the EPB system. REFER to ELECTRONIC PARKING BRAKE (EPB) RESETTING in this article .
I5 CHECK CIRCUIT 75-CG14 (YE/GN) FOR AN OPEN
- Measure the resistance between the EPB switch C3218-7, circuit 75-CG14 (YE/GN), harness side and the CJB fuse 7 (5A) output cavity.
  
  Fig 5: Measuring Resistance Between EPB Switch C3218-7, Circuit 75-CG14 (YE/GN), Harness Side And CJB Fuse 7 (5A) Output Cavity
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms
- Yes : INSTALL a new EPB module. REFER to PARKING BRAKE MODULE in this article . CLEAR the DTC(s). REPEAT the self-test. RESET the EPB system. REFER to ELECTRONIC PARKING BRAKE (EPB) RESETTING in this article .
- No : REPAIR the circuit. CLEAR the DTC(s). REPEAT the self-test. RESET the EPB system. REFER to ELECTRONIC PARKING BRAKE (EPB) RESETTING in this article .