GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2009 🢒 XLR 🢒 Driver Information and Entertainment 🢒 Cellular, Entertainment, and Navigation 🢒 DTC B1370

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC B1370: Device Ignition 1 Circuit

Circuit/System Description

The remote control door lock receiver (RCDLR) provides an high side drive output for the ignition 1 voltage circuit. The ignition 1 voltage circuit controls the Run/Crank relay when the backup power mode is enabled.

Conditions for Running the DTC

Voltage supplied to the module is in the normal operating voltage range of 9-16 V.

Conditions for Setting the DTC
    • The RCDLR detects a short to ground in the ignition 1 voltage circuit when the output is active for greater than 0.375 second.
    • The RCDLR detects a short to B+ or an open in the ignition 1 voltage circuit when the output is inactive for greater than 0.375 second.

Action Taken When the DTC Sets

The RCDLR disables the output for the current ignition cycle when a short to ground is detected.

Conditions for Clearing the DTC
    • A current DTC clears when the malfunction is no longer present.
    • A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Reference Information

Schematic Reference

Power Moding Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

    •  Retained Accessory Power Description and Operation
    •  Power Mode Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing
  1. Ignition OFF, disconnect the Run/Crank relay.
  2. Connect a test lamp between the coil cavities of the Run/Crank relay.
  3. Ignition ON, verify DTC B1370 is set as current.
    4. ⇒If DTC is not set as current, replace the Run/Crank relay.
  4. Ignition OFF, connect the Run/Crank relay.
  5. Disconnect the X4 harness connector at the BCM and remove the ignition 1 voltage circuit terminal C8.
  6. Connect the X4 harness connector at the BCM.
  7. Ignition ON, verify DTC B1370 is set as current.
    8. ⇒If DTC is not set as current, test the BCM ignition 1 voltage circuit between harness connector X4 terminal D3 and harness connector X3 terminal B5 for a short to voltage, short to ground, or an open/high resistance. If circuit test normal, replace the BCM.
  8. Connect at test lamp from the ignition 1 voltage circuit terminal C8 of the BCM and ground.
  9. With a scan tool, command the Run/Crank relay ON. The test lamp should turn ON and OFF when switching between the commanded states.
    10. ⇒If the test lamp is always ON, test the ignition 1 voltage circuit between the RCDLR harness connector X4 terminal C8 and the BCM for a short to voltage.
    ⇒If the test lamp is always OFF, test the ignition 1 voltage circuit between the RCDLR harness connector X4 terminal C8 and the BCM for a short to ground or an open/high resistance.
  10. If all circuits test normal, replace the RCDLR.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM, and RCDLR replacement, setup, and programming