Chevrolet Silverado / GMC Sierra. Service manual — part 1692

The SOC at key-on is 30 percent lower than when the engine was last running.

The battery drain is more than 2 amps.

Action Taken When the DTC Sets

No actions are taken. This DTC serves only as an aid to the technician.

Conditions for Clearing the DTC

The DTC will clear when the SOC is greater than or equal to 80 percent.

A history DTC clears after 50 consecutive ignition cycles that the diagnostic runs and does
not fail.

Reference Information

Schematic Reference

Starting and Charging Schematics

Auxiliary Battery Schematics (TP2)

Connector End View Reference

Component Connector End Views

Description and Operation

Charging System 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

Diagnostic Aids

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Electrical - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

This DTC indicates that the cause of a discharged battery is likely a parasitic current draw,
rather than a defective battery.

If the vehicle is equipped with an auxiliary battery (TP2), verify that there is not a fuse
installed in the STUD 1 Fuse 70 position of the underhood fuse block. A plastic plug may
be installed in this position instead of a fuse. If a fuse is installed in this position and any
optional equipment is powered by the auxiliary battery, it will discharge the primary battery
in addition to the auxiliary battery.

Verify that all accessories are turned OFF, including optional accessories that the vehicle
may have been wired for, but does not have installed, such as auxiliary lights. If an optional
accessory swich is left in the ON position, it may energize a relay that will discharge the
battery over time, even if the accessory is not installed on the vehicle.

A battery discharging for no apparent reason while the vehicle is parked can be caused by
an intermittent draw, such as a module waking up, or a continuous draw, such as a dome
light or stuck relay. Look and listen for any components that may be operating when they
should turn off, such as a fuel pump.

Circuit/System Verification

Ignition ON, compare the scan tool Prev. State of Charge and Start Up State of Charge
parameters, in Body Control Module, Data Display, Charging Info. The readings should not
differ by more than 30 percent.

Circuit/System Testing

Go to Battery Electrical Drain/Parasitic Load Test.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

DTC C0899

Diagnostic Instructions

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Review Strategy Based Diagnosis for an overview of this diagnostic approach.

Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC C0899 00

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Electrical - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

Device Voltage Low - EBCM (JF3/JF7/JH6/JH7)

DTC C0899 03

Device Voltage Low - EBCM (JL4), PTO (M1F)

Diagnostic Fault Information

Circuit/System Description

The electronic brake control module (EBCM) and the power take off module (PTOM), if
equipped, monitor the battery positive (B+) voltage level available for system operation. A low
voltage condition prevents the system from operating properly. If low voltage is detected by the
EBCM or PTOM, then DTC C0899 sets.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The ignition voltage available to the EBCM or PTOM is less than 9 volts for 100 msec.

Action Taken When the DTC Sets

Eletronic Brake Control Module (EBCM)

The traction control system (TCS) and vehicle stability enhancement system (VSES) are
disabled for the duration of the ignition cycle.

The vehicle dynamics caution (VDC) indicator turns ON.

Power Take-Off Module (PTOM)

The PTO (M1F) is disabled for the duration of the ignition cycle.

Conditions for Clearing the DTC

Circuit

Short to

Ground

Open/High

Resistance

Short to

Voltage

Signal

Performance

B+

C0899 00,

C0899 03

C0899 00,

C0899 03

-

-

Ground

-

C0899 00,

C0899 03

-

-

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Electrical - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

The condition for the DTC is no longer present.

The EBCM automatically clears the history DTC when a current DTC is not detected in 100
consecutive drive cycles.

Diagnostic Aids

A low voltage DTC in multiple modules indicates a concern in the charging system.

Inspect the ground connections G103 and G300 to insure that they are clean and tight.

Reference Information

Schematic Reference

Starting and Charging Schematics

Antilock Brake System Schematics

Power Take-Off (PTO) Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Charging System Description and Operation

ABS Description and Operation (With JL4) or ABS Description and Operation
(Without JL4)

Power Take-Off (PTO) 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

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Electrical - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado