2010 Cadillac CTS Sedan AWD V6-3.6L Page 215
4. Ignition ON, test for 4.0 - 8.5 volts between the control circuit terminal 1 and ground.
瀚慖f less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace
the BCM.
瀚慖f greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
5. Ignition OFF, connect the harness connector at the windshield outside moisture sensor.
6. Disconnect the X4 harness connector at the BCM.
7. Ignition ON, test for 8.0 - 10.0 volts between the signal circuit terminal 18 and ground.
瀚慖f less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace
the windshield outside moisture sensor.
瀚慖f greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the windshield outside
moisture sensor.
8. If all circuits test normal, replace the BCM.
Repair Instructions
* Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Control Module References (See: Testing and Inspection/Programming and Relearning) for BCM replacement, setup, and programming
* Windshield Outside Moisture Sensor Replacement (See: Sensors and Switches/Sensors and Switches - Wiper and Washer Systems/Rain
Sensor/Service and Repair)
B370D
DTC B370C or B370D
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptor
DTC B370C 00
- Rain Sensor Intensity Signal Circuit.
DTC B370D 00
- Rain Sensor Mode Control Circuit.
Diagnostic Fault Information
Circuit/System Description
Ignition voltage is supplied to the windshield outside moisture sensor from the body control module (BCM). Whenever the ignition is in the run or
accessory positions, the BCM sends the wiper/washer switch status using a pulse width modulated (PWM) signal through the windshield outside
moisture sensor control circuit to the outside moisture sensor. When a wipe cycle is needed, the moisture sensor sends a PWM voltage signal
through the moisture sensor signal circuit back to the BCM requesting the wiper operation.
The windshield outside moisture sensor uses the moisture sensor control circuit to command wiper motor wipe cycles and to confirm the moisture
sensor signal circuit is being received. If at anytime communication between the windshield outside moisture sensor and BCM is lost, the BCM will
use the inputs from the windshield wiper/washer switch in the delay positions to operate the wiper motor at continuous variable delay intervals.
Conditions for Running the DTC
