B1981
DTC B1981 Battery Voltage Low:
Refer to Instrument Cluster: Analog Schematics Electrical Diagrams
CIRCUIT DESCRIPTION
The battery positive voltage (B+) is supplied to the Instrument Cluster (IPC) on CKT 440 (ORN) at connector C2 terminal A1. The IPC monitors this voltage to determine if it is within a valid operating range and the alternator is operating properly.
CONDITIONS FOR SETTING DTC
^ The battery positive voltage (B+) level falls below 9 volts for approximately 1.2 seconds or more.
^ Engine RPM is greater than 1500 rpm.
^ The alternator is not operating properly. The IPC receives this status from the Powertrain Control Module (PCM) via Class 2 message.
ACTION TAKEN WHEN THE DTC SETS
^ DTC B1981 is stored in the IPC memory.
^ The IPC does not respond to inputs when the voltage is less than 9 volts.
^ BATTERY VOLTAGE LOW message is displayed on the DIC.
^ DTC B1983 does not set when DTC B1981 is current.
^ Other IPC DTCs do not set while DTC B1981 is current.
CONDITIONS FOR CLEARING DTC
^ This DTC clears (status changes from current to history when the Battery Positive Voltage (B+) level rises above 9.5 volts for approximately 1.2 seconds and alternator output, as reported by the PCM, is normal.
^ A history DTC clears after 50 consecutive ignition cycles if the Conditions for setting DTC are no longer present.
^ Current and history DTCs may be cleared using a scan tool or using the IPC on-board clearing DTCs feature.
DIAGNOSTIC AIDS
The IPC does not check for low battery positive voltage (B+) during and for 2 seconds following the engine START mode. This delay ensures that DTC B1981 will not erroneously set.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table:
1. Perform the Instrument Cluster (IPC) Diagnostic System Check before continuing with the diagnosis of this DTC.
2. Checks that DTC was not set erroneously.
3. Determines whether the malfunction is in the charging system or the Instrument Cluster (IPC).
5. Clear all DTCs after the repair procedure is complete.