B370A
DTC B370A
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptor
DTC B370A 39
-
Rain Sensor Internal Malfunction
Diagnostic Fault Information
Circuit/System Description
B+ voltage is supplied to the windshield outside moisture sensor. Whenever the ignition is ON, or in accessory positions, the body control module (BCM), sends the turn signal/multifunction switch status by using a pulse width modulated (PWM) signal. When a wipe cycle is needed, the windshield outside moisture sensor sends a PWM voltage signal to the BCM, initiating the wiper operation. The BCM commands the windshield wiper motor wipe cycles. If a fault occurs at any time between the windshield outside moisture sensor and BCM, the BCM will use the inputs from the turn signal/multifunction switch in the delay positions to operate the windshield wiper motor at continuous variable delay intervals.
Conditions for Running the DTC
* Ignition ON.
* The system voltage is between 9-16 V.
Conditions for Setting the DTC
The BCM receives an invalid signal from the windshield outside moisture sensor.
Action Taken When the DTC Sets
* If the BCM looses communication with the windshield outside moisture sensor while the windshield outside moisture sensor was requesting single wipes, it shall fail soft the wipers operation to front wiper manual - intermittent with a fixed dwell time of 4 seconds.
* If the BCM looses communication with the windshield outside moisture sensor while the windshield outside moisture sensor was continuously requesting low, it shall fail soft the wipers operation to front wiper manual - low.
* If the BCM looses communication with the windshield outside moisture sensor while the windshield outside moisture sensor was continuously requesting high, it shall fail soft the wipers operation to front wiper manual - high.
Conditions for Clearing the DTC
A current DTC clears when the diagnostic runs and passes.
Reference Information
Schematic Reference
Wiper/Washer Schematics Electrical Diagrams
Connector End View Reference
Component Connector End Views Sunshade - Left
Description and Operation
Wiper/Washer System Description and Operation Description and Operation
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Programming and Relearning for scan tool information
Circuit/System Verification
Ignition ON, S82 Windshield Wiper/Washer Switch in the low position. The windshield wipers should operate at low speed.
If the windshield wipers do not operate, refer to Windshield Wiper System Malfunction Windshield Wiper System Malfunction.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the B117 Rain Sensor.
2. Test for less than 5 ohms between the ground circuit terminal 2 and ground.
• If greater than the specified value, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that a test lamp illuminates between B+ voltage circuit terminal 1 and ground.
• If the test lamp does not illuminate, test the B+ voltage circuit for a short to ground or an open/high resistance.
4. Ignition ON, test for 4-12 V between the signal circuit terminal 3 and ground.
• If less than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the K9 Body Control Module.
5. If all circuits test normal, replace the B117 Rain Sensor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Windshield Outside Moisture Sensor Replacement Windshield Outside Moisture Sensor Replacement
* Control Module References Programming and Relearning for BCM replacement, setup, and programming