Electrical Circuit Inspection Procedure

CHECK OPEN CIRCUIT
1. Procedures for Open Circuit
  - Continuity Check
  - Voltage Check
  If an open circuit occurs (as seen in Fig 1), it can be found by performing Step 2 (Continuity Check Method) or Step 3 (Voltage Check Method) as shown in Fig 1.
  
  Fig 1: Checking Voltage
  Courtesy of KIA MOTORS AMERICA, INC.
2. Continuity Check Method
  NOTE: When measuring for resistance, lightly shake the wire harness above and below or from side to side.
  
  Specification (Resistance)
  
  1 Ω or less → Normal Circuit
  
  1 MΩ or Higher → Open Circuit
  1. Disconnect connectors (A), (C) and measure resistance between connector (A) and (C) as shown in Fig 2.
    In Fig 2, the measured resistance of line 1 and 2 is higher than 1 MΩ and below 1 Ω respectively. Specifically the open circuit is line 1 (Line 2 is normal). To find exact break point, check sub line of line 1 as described in next step.
    
    Fig 2: Checking Resistance Between Lines 1 & 2
    Courtesy of KIA MOTORS AMERICA, INC.
  2. Disconnect connector (B), and measure for resistance between connector (C) and (B1) and between (B2) and (A) as shown in Fig 3.
    In this case the measured resistance between connector (C) and (B1) is higher than 1MΩ and the open circuit is between terminal 1 of connector (C) and terminal 1 of connector (B1).
    
    Fig 3: Checking Resistance Between Connector (C) & (B1)
    Courtesy of KIA MOTORS AMERICA, INC.
3. Voltage Check Method
  1. With each connector still connected, measure the voltage between the chassis ground and terminal 1 of each connectors (A), (B) and (C) as shown in Fig 4.
    The measured voltage of each connector is 5V, 5V and 0V respectively. So the open circuit is between connector (C) and (B).
    
    Fig 4: Checking Voltage Between Chassis Ground & Terminal 1 Of Each Connectors (A), (B) & (C)
    Courtesy of KIA MOTORS AMERICA, INC.
CHECK SHORT CIRCUIT
1. Test Method for Short to Ground Circuit
  - Continuity Check with Chassis Ground
  If short to ground circuit occurs as shown in Fig 5, the broken point can be found by performing Step 2 (Continuity Check Method with Chassis Ground).
  
  Fig 5: Checking Continuity
  Courtesy of KIA MOTORS AMERICA, INC.
2. Continuity Check Method (with Chassis Ground)
  NOTE: Lightly shake the wire harness above and below, or from side to side when measuring the resistance.
  
  Specification (Resistance)
  
  1Ω or less → Short to Ground Circuit
  
  1MΩ or Higher → Normal Circuit
  1. Disconnect connectors (A), (C) and measure for resistance between connector (A) and Chassis Ground as shown in Fig 6.
    The measured resistance of line 1 and 2 in this example is below 1 Ω and higher than 1MΩ respectively. Specifically the short to ground circuit is line 1 (Line 2 is normal). To find exact broken point, check the sub line of line 1 as described in the next step.
    
    Fig 6: Checking Resistance Between Chassis Ground And Lines 1 & 2
    Courtesy of KIA MOTORS AMERICA, INC.
  2. Disconnect connector (B), and measure the resistance between connector (A) and chassis ground, and between (B1) and chassis ground as shown in Fig 7.
    The measured resistance between connector (B1) and chassis ground is 1Ω or less. The short to ground circuit is between terminal 1 of connector (C) and terminal 1 of connector (B1).
    
    Fig 7: Checking Resistance Between Connector (B1) & Chassis Ground
    Courtesy of KIA MOTORS AMERICA, INC.