For 1990-2009 cars only
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 Descriptors
DTC B1566: Current Sensor Polarity Check - GBCMCircuit/System Description
The generator battery control module (GBCM) monitors its internal battery current sensor for charging system operations, and also for diagnostic purposes. If reversed polarity of the battery current is sensed, then DTC B1566 will set.
Conditions for Running the DTC
| • | The engine is not running. |
| • | DTC B1516 is not set. |
Conditions for Setting the DTC
The GBCM detects positive battery current.
Action Taken When the DTC Sets
The regulated voltage control (RVC) is disabled.
Conditions for Clearing the DTC
The GBCM detects correct polarity of the battery current.
Diagnostic Aids
DTC B1566 may set if a battery charger is used.
Reference Information
Schematic Reference
Starting and Charging Schematics
Connector End View Reference
Description and Operation
Charging System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Verify that the GBCM is installed correctly. The GBCM should be installed on the negative battery cables, with the sensor coil around the negative cables and facing away from the battery, and with the harness connector facing toward the battery.
- Ignition ON, clear the DTC with the scan tool. Verify that DTC B1566 does not set.
| ⇒ | If the GBCM is installed backwards or incorrectly, remove and reinstall the GBCM. |
| ⇒ | If the DTC sets, replace the GBCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for GBCM replacement, setup, and programming.
