Circuit/System Testing

Rain Sensor Switch Malfunction

1. Ignition OFF, disconnect the X1 and X3 harness connectors at the S78 Turn Signal/Multifunction Switch.
2. Test for less than 10 Ω between the low reference circuit terminal 7 X1 and ground.
   • If 10 Ω or greater 
   1. Ignition OFF.
   2. Test for less than 2 Ω in the ground circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K9 Body Control Module.
   • If less than 10 Ω 
3. Verify the scan tool Rain Sensor parameter is Inactive.
   • If not Inactive 
   1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module,
   2. Test for infinite resistance between the signal circuit terminal 4 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K9 Body Control Module,
   • If Inactive 
4. Install a 3 A fused jumper wire between the signal circuit terminal 4 X3 and the low reference circuit terminal 7 X1.
5. Verify the scan tool Rain Sensor parameter is Active.
   • If not Active 
   1. Ignition OFF, remove the jumper wire, disconnect the harness connector at the K9 Body Control Module, ignition ON.
   2. Test for less than 1 V between the signal circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V
   3. Test for less than 2 Ω in the signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K9 Body Control Module,
   • If Active 
6. Test or replace the S78 Turn Signal/Multifunction Switch.

Rain Sensor Module Malfunction

1. Ignition OFF, all vehicle systems OFF, disconnect the harness connector at the B200 Rain Sensor Module. It may take up to 2 min for all vehicle systems to power down.
2. Test for less than 10 Ω between the ground circuit terminal 3 and ground.
   • If 10 Ω or greater 
   1. Ignition OFF.
   2. Test for less than 2 Ω in the ground circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, repair the open/high resistance in the ground connection.
   • If less than 10 Ω 
3. Ignition ON.
4. Verify a test lamp illuminates between the B+ circuit terminal 1 and ground.
   • If the test lamp does not illuminate and the circuit fuse is good 
   1. Ignition OFF, remove the test lamp.
   2. Test for less than 2 Ω in the B+ circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
   • If the test lamp does not illuminate and the circuit fuse is open 
   1. Ignition OFF, remove the test lamp.
   2. Test for infinite resistance between the B+ circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the B200 Rain Sensor Module.
   • If the test lamp illuminates 
5. Test for 5.0 - 10.0 V between the serial data circuit terminal 2 and ground.
   • If less than 5.0 V 
   1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
   2. Test for infinite resistance between the serial data circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
   3. Test for less than 2 Ω in the serial data circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K9 Body Control Module.
   • If greater than 10.0 V 
   1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module, ignition ON.
   2. Test for less than 1 V between the serial data circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K9 Body Control Module.
   • If between 5.0 - 10.0 V 
6. Test or replace the B200 Rain Sensor Module.