Battery Pack Voltage Out Of Range

OBD II fault code B1676 is a manufacturer-specific trouble code that is defined by carmakers Ford, Lincoln, Mercury, Mazda, Jaguar, and Mazda as “Battery Pack Voltage out Of Range”, and is set when the PCM (Powertrain Control Module) detects an abnormal battery voltage. NOTE: It should be noted that the definition “Battery Pack Voltage out Of Range” could be confusing, if not downright misleading.

In generally accepted automotive jargon, a “battery pack” typically refers to a series of batteries that are connected to form a “pack of batteries” such as the high-voltage battery packs one finds in hybrid and electric vehicles. In practice though, this code is used by some manufacturers to refer to the two batteries found in some pick-up trucks with large diesel engines, hence the tenuous reference to a “battery pack”.

The reasons for the inclusion of the word “pack” in some resources are not clear, though. Nonetheless, in most resources and databases maintained by carmakers that have assigned code B1676 to battery voltage issues, code B1676 is defined as “Battery Voltage out Of Range”, without reference being made to a battery “pack”.

There are many examples of trouble codes that seem to indicate problems with a particular part, system, or component, when in fact, the code refers to something else entirely, and in the case of code B1676, the confusion around the wording of its definition extends to the problems it has come to describe.

Code B1676 is a good example of how some codes have ambiguous meanings; on the surface, code B1676 appears to be related to low battery voltages on the vehicle makes listed above, when, in fact, it refers to faults, failures, malfunctions, and defects mainly in the ABS braking systems of these vehicles.

Here is how it works- One of the requirements of an advanced ABS braking system is that it should be supplied with a constant voltage/current that is maintained within a range of minimum and maximum allowable values to reduce the possibility that the operation of associated systems such as Stability Control, Traction Control, Adaptive Cruise Control, Electronic Brake Distribution, Accident Mitigation, and others can be affected negatively.

In a fully functional system, the battery voltage to the ABS control module, which largely manages the associated systems listed above in conjunction with dedicated control modules, will remain relatively constant, and minor fluctuations in current and/or voltage supplied to the ABS system will not have noticeable effects on the operation of these systems.

However, in practice, the ABS system, and particularly the ABS control modules and their associated wiring on listed vehicles are not particularly fault-tolerant, which is compounded by the fact that the PCM interprets faults, failures, defects, and malfunctions in the ABS control module and associated wiring as low battery voltages- for reasons that are not entirely clear.

As a practical matter though, fluctuations that are large enough to trigger code B1676 are almost invariably caused by malfunctions and/or defects in failing or failing ABS control modules or in less-than-perfect associated wiring, as opposed to being caused by damaged, defective, or discharged batteries that are impeding current flow to, or through one or more systems/components such as the ABS control module and associated safety systems whose correct operation depend entirely on the ABS module working correctly.

Nonetheless, code B1676 will set on listed vehicles if any fault, failure, defect, or malfunction in the ABS control module and/or its associated wiring causes the PCM to measure the voltage that is supplied to the ABS control module as being below 9V, or above 19V for longer than 8 consecutive seconds.