B370D
DTC B370C or B370D
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 Descriptors
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 rain 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 rain sensor control circuit to the rain sensor. When a wipe cycle is needed, the rain sensor sends a PWM voltage signal through the rain sensor signal circuit back to the BCM requesting the wiper operation.
The windshield outside rain sensor uses the rain sensor control circuit to command wiper motor wipe cycles and to confirm the rain sensor signal circuit is being received. If at anytime communication between the windshield outside rain 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
Ignition in Run or Accessory positions.
Conditions for Setting the DTC
B370C
An open or short to ground has been detected on the signal circuit.
B370D
An open or short to ground has been detected on the signal circuit.
Action Taken When the DTC Sets
Rain sensitive wiper operation is suspended so long as the fault is present. The wipers will still operate normally in all other modes.
Conditions for Clearing the DTC
* A current DTC will clear when the fault is no longer present.
* A history DTC will clear after 40 malfunction-free ignition cycles.
Reference Information
Schematic Reference
Wiper/Washer Schematics Electrical Diagrams
Connector End View Reference
Component Connector End Views A/C Compressor Clutch
Description and Operation
Wiper/Washer System Description and Operation (Wiper and Washers) Wiper/Washer System (Wipers and Washers)
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 Control Module References for scan tool information
Circuit/System Testing
1. Ignition OFF and all vehicle systems OFF, disconnect the B117 rain sensor. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the ground circuit terminal 3 and ground.
• If 10 ohms or greater
1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms
3. Ignition ON.
4. Verify a test lamp illuminates between the ignition circuit terminal 4 and the ground circuit terminal 3.
• If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF.
2. Test for less than 2 ohms in the ignition circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, verify the fuse is OK and there is voltage at the circuit.
• If the test lamp does not illuminate and the circuit fuse is open
1. Ignition OFF.
2. Test for infinite resistance between the ignition circuit and ground.
• If less than infinite resistance, repair the short to ground in the circuit.
• If infinite resistance, replace the K9 body control module.
• If test lamp illuminates
5. Test for 500-900 ohms between the signal circuit terminal 1 and ground.
• If less than 500 ohms
1. Disconnect the X4 harness connector at the K9 body control module.
2. Test for infinite resistance between the signal circuit 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 greater than 900 ohms
1. Disconnect the X4 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. Ignition OFF.
4. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 body control module.
• If between 500-900 ohms
6. Test for 8-10 V between the control circuit terminal 2 and ground.
• If less than 8 V
1. Ignition OFF, disconnect the X4 harness connector at the K9 body control module.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Ignition OFF.
4. Test for less than 2 ohms in the control circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 body control module.
• If greater than 10 V
1. Disconnect the X4 harness connector at the K9 body control module.
2. Test for less than 1 V between the control 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 8-10 ohms
7. 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 Service and Repair
* Control Module References Control Module References for BCM replacement, programming and setup