Vehicle Code 23154 makes it unlawful for anyone on DUI probation to drive with a blood-alcohol concentration of 0.01 percent or greater, a near-zero limit far below the standard 0.08. I am Joel Brand, and here is what the statute requires and how I defend a charge under it.
The text of the law
Vehicle Code 23154. (a) It is unlawful for a person who is on probation for a violation of Section 23152 or 23153 to operate a motor vehicle at any time with a blood-alcohol concentration of 0.01 percent or greater, as measured by a preliminary alcohol screening test or other chemical test. (b) A person may be found to be in violation of subdivision (a) if the person was, at the time of driving, on probation for a violation of Section 23152 or 23153, and the trier of fact finds that the person had consumed an alcoholic beverage and was driving a vehicle with a blood-alcohol concentration of 0.01 percent or greater, as measured by a preliminary alcohol screening test or other chemical test.
What the statute requires
Section 23154 codifies the "zero tolerance" condition that comes with DUI probation. Anyone placed on probation for a DUI under Vehicle Code 23152 or a DUI-causing-injury under Vehicle Code 23153 agrees, as a term of that probation, not to drive with any measurable alcohol. The threshold is just 0.01 percent, an amount so low that it can reflect a single drink, and it is established by a preliminary alcohol screening device at the roadside or another chemical test. The two elements are simple: the person was on DUI probation, and they drove with a measured level at or above 0.01.
The near-zero threshold cuts both ways
The extremely low limit is the defining feature of these cases, and it makes the accuracy of the measurement everything. At 0.01 percent, the margin for error in a roadside screening device, the effects of mouth alcohol, recent use of mouthwash or breath spray, certain medical conditions, and the timing of the test all loom large. A reading that low is well within the range where instrument variability and contamination can produce a false positive. Because the line is so close to zero, a small measurement problem is the difference between a violation and none, which is exactly where I focus.
The probation status is an element
A 23154 charge depends on the person actually being on DUI probation at the time. That sounds straightforward, but it is worth verifying: whether probation was still in effect on the date of driving, whether it had expired or been terminated, and whether the underlying DUI probation was validly imposed. If the person was not in fact on qualifying probation, the charge under this statute does not apply.
Challenging the stop and the screening
The standard defenses apply. The stop must have been lawful; if it was not, a motion to suppress under Penal Code 1538.5 can exclude the evidence that followed, including the screening result. And the screening device itself must be reliable, properly calibrated, and correctly administered. Preliminary alcohol screening devices are handheld units that are particularly susceptible to error, and challenging their calibration and the conditions of the test is central to defending a 23154 case.
It usually means a probation violation too
A 23154 charge typically arrives alongside an alleged violation of the existing DUI probation, since driving with measurable alcohol breaches a standard condition. That probation violation exposes the person to the suspended jail time from the original case, which is often the larger threat. Defeating or undermining the 23154 measurement therefore does double duty: it answers the new charge and removes the basis for the probation violation. I handle both together, because they rise and fall on the same disputed reading.
It is an infraction, but the stakes are real
A violation of 23154 is itself an infraction, not a new misdemeanor DUI, but its real significance lies in the probation consequences and the additional license suspension it can trigger through the DMV. The combination of a low, error-prone threshold and serious collateral consequences is exactly why these charges should not simply be conceded. A careful challenge to the measurement and the stop is frequently worthwhile.
How these cases resolve
The realistic goals are to challenge the reliability of the low-level reading, to attack the lawfulness of the stop, to verify the probation status, and to keep any probation violation from triggering the suspended jail exposure from the original DUI. Where the screening result is unreliable or the stop does not hold up, the charge and the related violation can be defeated. As with every DUI matter, the outcome depends on the strength of the evidence, which is why I examine the device records and the stop in detail.
The preliminary screening device deserves scrutiny
The roadside preliminary alcohol screening device is the linchpin of most 23154 cases, and it is more fallible than its routine use suggests. These handheld units must be calibrated and maintained on a regular schedule, and they can be thrown off by residual mouth alcohol, recent use of breath products, certain diets, and even the operator's technique. Unlike the evidential breath instruments at the station, screening devices are designed for quick field use and carry a wider margin of error, which is precisely why a reading right at the 0.01 threshold should never be accepted at face value. I request the calibration and maintenance logs for the specific device and examine how and when the test was given, because at this threshold those records frequently reveal the difference between a real violation and a false positive.
How it fits the larger defense
Section 23154 is the zero-tolerance rule for those already on DUI probation, and it is defended with the same tools as any alcohol case: attacking the stop and the chemistry. It connects directly to the underlying VC 23152 probation. See my top DUI defenses and the defenses guide.
Accused of driving with alcohol while on DUI probation? Let's talk.
At 0.01 percent the measurement is everything, and testing its reliability is exactly what I do. Use the free case analysis on this page, or call me directly at (888) 271-6644. I answer my own phone, 24/7.