C1252: Hybrid brake booster or actuator fault (Toyota, Lexus) or vacuum pump control circuit (Chrysler, Jeep, Ram)
Brake booster fault or vacuum pump circuit
Severity: Inspect soon
Toyota bulletins tie C1252 to the brake, ABS or TRAC lights, and Toyota says to have the car inspected immediately when the ABS light is on; FCA ties it to the ESC light, which FCA says needs a dealer as soon as possible.
It gets more serious if:
- Stop: Stop in a safe place and call a dealer if the red brake warning light is on or the brake pedal feels different.
- Stop: On a Chrysler, Jeep or Ram, stop and have it checked immediately if the red brake warning light comes on.
C1252 in short
On Toyota and Lexus hybrids, C1252 is one of four codes Toyota uses to confirm a hybrid brake booster or actuator fault, usually a small internal fluid leak. On Chrysler, Jeep and Ram it is a vacuum pump control circuit fault. If the red brake light is on, stop and call a dealer; otherwise get it inspected promptly.
Toyota and Lexus hybrids use an electric pump and a pressure accumulator to power the brakes. Toyota's bulletin summaries do not define C1252 on its own; a hybrid repair shop reference, not Toyota, says it means the pump ran longer than expected.
Toyota and Lexus have issued many bulletins for hybrids that show the brake, ABS or TRAC warning lights, or a Check VSC message, with C1391, C1252, C1253 or C1256 stored. They say a small brake fluid leak inside the brake booster with master cylinder, or inside the brake actuator on other models and years, may be the cause.
On Chrysler, Jeep and Ram vehicles, C1252-92 means something else: a fault in the control circuit of an electric vacuum pump. FCA bulletin S1805000006 covers it with the ESC light on, sometimes with P258B. Either way it is a brake fault, so diagnosis belongs with a dealer.
Pick your make
C1252 is a manufacturer-specific code: its meaning depends on who built the car.
Other makes: meaning not verified. Check with a scan tool that reads manufacturer definitions.
Most likely causes
Cause 1: Brake booster pump assembly fault
Supported by vehicle data- Why it ranks here
- Customer Support Program 24TE01 replaces the brake booster pump along with the booster when this group of codes is stored, and a Mitchell 1 repair article does the same on 2011–2015 Prius. A hybrid repair shop reference ties C1252 to pump run time.
- What would change this
- Rises when C1252 appears with C1391 or C1256 on a covered model.
Cause 2: Small internal brake fluid leak in the brake booster with master cylinder
Supported by vehicle data- Why it ranks here
- Toyota and Lexus bulletins for the 2011–2015 Prius and Prius Plug-in, 2012–2018 Prius v, 2012–2014 Prius c, 2012–2014 Camry Hybrid and 2011–2014 CT 200h name this leak when C1252 and the brake warning lights appear.
- What would change this
- Rises on those models, and when C1391, C1252, C1253 and C1256 are stored together.
Cause 3: Small internal brake fluid leak in the brake actuator
Supported by vehicle data- Why it ranks here
- Toyota and Lexus bulletins for the 2004–2009 Prius, 2006–2019 Highlander hybrids, 2007–2011 Camry HV, 2015–2017 Prius c and 2014–2017 CT 200h name an internal leak in the brake actuator for the same group of codes.
- What would change this
- Rises on those models; the bulletin for your exact model and year decides which part is meant.
Cause 4: Electric vacuum pump or its control circuit (Chrysler, Jeep, Ram)
Supported by vehicle data- Why it ranks here
- FCA bulletin S1805000006 covers the ESC light with C1252-92 vacuum pump control circuit, or P258B electronic vacuum pump performance, on Pacifica, Cherokee, Wrangler, Gladiator and Ram 1500.
- What would change this
- Applies on those FCA models; rises if P258B is also stored.
Cause 5: Low brake fluid or an outside leak
Possible — needs testing- Why it ranks here
- Toyota's owner's manual says the red brake light can mean low brake fluid. The bulletins describe internal leaks, so an outside leak is a separate check, not the usual cause.
- What would change this
- Rises if the reservoir level is low or there is fluid on a wheel or under the car.
What to test first
Start at step 1. Each result tells you what it means and where to go next.
Step 1: Note which warning lights are on (red brake light, ABS, TRAC, Check VSC) and whether the brake pedal feels different.
IfThe red brake warning light is on or the pedal feels different
It meansToyota says to stop in a safe place and contact a dealer. Do not keep driving.
IfOnly the ABS, TRAC or Check VSC warning is on
It meansBrake assist or stability help may be off. Have it inspected right away.
Step 2: Have all chassis codes read with a scan tool that reads the maker's brake codes, note any subcode (such as -92), and note whether C1391, C1252, C1253 and C1256 are stored together.
IfThe vehicle is a Chrysler, Jeep or Ram and C1252-92 is stored
It meansThis is FCA's vacuum pump control circuit code. Ask an FCA dealer to check bulletin S1805000006.
Points to: Electric vacuum pump or its control circuit (Chrysler, Jeep, Ram)
IfC1252 is stored with one or more of the other three
It meansThis matches the pattern in Toyota's bulletins for an internal leak in the booster or actuator.
IfC1252 is stored alone
It meansStill have the bulletin checked, but the dealer's full diagnosis matters more.
Step 3: With the car parked, look at the brake fluid level through the side of the reservoir under the hood without opening it, and look for fluid at the wheels or under the car.
IfThe level is low or there is fluid outside
It meansThere may be an outside leak. Do not drive; have it towed or checked where it sits.
IfThe level looks normal and nothing is wet
It meansAn internal leak, as the bulletins describe, is more likely.
Step 4: Have a Toyota or Lexus dealer check the VIN for the bulletin and Customer Support Program 24TE01, then follow the bulletin's diagnosis.
Warning:Dealer procedure on the hybrid brake system, which can hold high fluid pressure. Do not open or bleed it yourself.
IfThe car is a 2011 or later Prius-family model, 2012–2014 Camry Hybrid or 2011–2014 CT 200h
It meansThe bulletin points to the brake booster with master cylinder.
Points to: Small internal brake fluid leak in the brake booster with master cylinder
IfThe car is an older Prius, a Highlander hybrid, a 2007–2011 Camry HV, a 2015–2017 Prius c or a 2014–2017 CT 200h
It meansThe bulletin points to the brake actuator.
Points to: Small internal brake fluid leak in the brake actuator
IfC1252 is stored with C1391 or C1256
It meansThe booster pump is running long because pressure is leaking away.
Symptoms
- Red brake warning light on Gets more serious: stop and have it checked.
- ABS warning light on
- TRAC light on or Check VSC message
- Brake pedal feels different than normal Gets more serious: stop and have it checked.
- ESC light on (Chrysler, Jeep, Ram)
How to fix
This is a safety-critical system, so we explain the code but don't give repair steps. Have it inspected by a qualified technician.
Parts and cost context
- Brake booster assembly with master cylinder:Named by the newer bulletins; one repair article says the booster pump is replaced with it. Labor varies; get a quote, and ask the dealer about 24TE01 coverage first.
- Brake actuator:Named by the bulletins for older and some later models. Labor varies; get a quote.
- Electric vacuum pump (Chrysler, Jeep, Ram):Named in FCA bulletin S1805000006. Labor varies; get a quote.
Labor varies by vehicle and shop; get a quote before you approve a repair.
Compare used part prices on PartPriceGuideOn your vehicle
ToyotaYour car
2004–2015 · Prius
Supported by vehicle dataToyota bulletins list this code with the brake, ABS or TRAC lights on 2004–2009 Prius (internal leak in the brake actuator) and 2011–2015 Prius and Prius Plug-in (internal leak in the brake booster with master cylinder). The bulletins are on NHTSA, but whether they are still current is not verified, so it is labelled vehicle data rather than confirmed.
Where it is:Brake actuator (2004–2009) or brake booster with master cylinder (2011–2015)
2006–2019 · Highlander
Supported by vehicle dataToyota bulletins cover 2006–2007 Highlander HV and 2008–2019 Highlander Hybrid for an internal leak in the brake actuator, and Customer Support Program 24TE01 covers the brake booster and booster pump on certain 2014–2016 Highlander HV. Hybrid models only. The bulletins are on NHTSA, but whether they are still current is not verified, so it is labelled vehicle data rather than confirmed.
Where it is:Brake actuator or brake booster assembly
2012–2018 · Prius V
Supported by vehicle dataToyota bulletins cover 2012–2018 Prius v for an internal leak in the brake booster with master cylinder, and 24TE01 adds coverage for certain 2017 models. The bulletins are on NHTSA, but whether they are still current is not verified, so it is labelled vehicle data rather than confirmed.
Where it is:Brake booster assembly with master cylinder
2012–2017 · Prius C
Supported by vehicle dataToyota bulletins cover 2012–2014 Prius c (brake booster with master cylinder) and 2015–2017 Prius c (brake actuator). The bulletins are on NHTSA, but whether they are still current is not verified, so it is labelled vehicle data rather than confirmed.
Where it is:Brake booster with master cylinder or brake actuator
2007–2014 · Camry
Supported by vehicle dataHybrid models only: 2007–2011 Camry HV (brake actuator) and 2012–2014 Camry Hybrid (brake booster with master cylinder). The 2012–2014 bulletin also covers the 2013–2015 Avalon Hybrid. The bulletins are on NHTSA, but whether they are still current is not verified, so it is labelled vehicle data rather than confirmed.
Where it is:Brake actuator or brake booster with master cylinder
T-SB-0032-16Status unverified
Brake, ABS and/or TRAC lights or Check VSC with C1391, C1252, C1253 or C1256
2004–2009prius, highlander · issued · NHTSA 10134400
2004–2009 Prius and 2006–2007 Highlander HV. Repair procedure for a small internal brake fluid leak inside the brake actuator. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
T-SB-0064-19Status unverified
Brake, ABS and/or TRAC lights or Check VSC with C1391, C1252, C1253 or C1256
2008–2010highlander · issued · NHTSA 10161541
2008–2010 Highlander Hybrid. Repair procedure for a small internal brake fluid leak inside the brake actuator. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
T-SB-0041-14Status unverified
Brake, ABS and/or TRAC lights or Check VSC with C1391, C1252, C1253 or C1256
2007–2011camry · issued · NHTSA 10132769
2007–2011 Camry HV. Repair procedure for a small internal brake fluid leak inside the brake actuator. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
T-SB-0024-19Status unverified
Brake, ABS and/or TRAC lights or Check VSC with C1391, C1252, C1253 or C1256
2011–2015prius, prius-plug-in · issued · NHTSA 10158575
2011–2015 Prius and 2012–2015 Prius Plug-in. Repair procedure for a small internal brake fluid leak inside the brake booster assembly with master cylinder. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
T-SB-0089-20Status unverified
Brake, ABS and/or TRAC lights or Check VSC with C1391, C1252, C1253 or C1256
2012–2014prius-v · issued · NHTSA 10181799
2012–2014 Prius v. Repair procedure for a small internal brake fluid leak inside the brake booster assembly with master cylinder. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
T-SB-0115-20Status unverified
Brake, ABS and/or TRAC lights or Check VSC with C1391, C1252, C1253 or C1256
2015prius-v · issued · NHTSA 10184562
2015 Prius v. Repair procedure for a small internal brake fluid leak inside the brake booster assembly with master cylinder. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
T-SB-0013-23Status unverified
Brake, ABS and/or TRAC lights or Check VSC with C1391, C1252, C1253 or C1256
2016–2018prius-v · issued · NHTSA 10234318
2016–2018 Prius v. A small brake fluid leak inside the brake booster assembly with master cylinder. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
T-SB-0028-21Status unverified
Brake, ABS and/or TRAC lights or Check VSC with C1391, C1252, C1253 or C1256
2012–2014prius-c · issued · NHTSA 10198129
2012–2014 Prius c. Repair procedure for a small internal brake fluid leak inside the brake booster assembly with master cylinder. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
TSB000824Status unverified
Brake, ABS and/or TRAC lights or Check VSC with C1391, C1252, C1253 or C1256
2015–2017prius-c · issued · NHTSA 10252260
2015–2017 Prius c. Repair procedure for a small internal brake fluid leak inside the brake actuator. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
TSB000924Status unverified
Brake, ABS and/or TRAC lights or Check VSC with C1391, C1252, C1253 or C1256
2014–2016highlander · issued · NHTSA 10252261
2014–2016 Highlander Hybrid. Repair procedure for a small internal brake fluid leak inside the brake actuator. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
T-SB-0014-25Status unverified
Brake, ABS and/or TRAC lights or Check VSC with C1391, C1252, C1253 or C1256
2017–2019highlander · issued · NHTSA 11014208
2017–2019 Highlander Hybrid. A small internal brake fluid leak inside the brake actuator. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
T-SB-0130-19Status unverified
Brake, ABS and/or TRAC lights or Check VSC with C1391, C1252, C1253 or C1256
2012–2015camry, avalon · issued · NHTSA 10165988
2012–2014 Camry Hybrid and 2013–2015 Avalon Hybrid. Repair procedure for a small internal brake fluid leak inside the brake booster assembly with master cylinder. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
24TE01Status unverified
Customer Support Program: brake booster and brake booster pump assemblies
2014–2017highlander, prius-v · issued · NHTSA 11011632
Extra coverage for internal brake booster faults on certain 2014–2016 Highlander HV and 2017 Prius v, verified by C1391, C1252, C1253 or C1256. Repair is a new brake booster and booster pump. Primary coverage ended March 31, 2025; secondary coverage runs 10 years or 150,000 miles from first use. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
LexusYour car
2011–2017 · CT
Supported by vehicle dataLexus bulletins cover the 2011–2014 CT 200h (brake booster with master cylinder) and 2014–2017 CT 200h (brake actuator). The bulletins are on NHTSA, but whether they are still current is not verified, so it is labelled vehicle data rather than confirmed.
Where it is:Brake booster with master cylinder or brake actuator
L-SB-0009-21Status unverified
Brake, ABS and/or TRAC lights or Check VSC with C1391, C1252, C1253 or C1256
2011–2014ct · issued · NHTSA 10198130
2011–2014 CT 200h. Repair procedure for a small internal brake fluid leak inside the brake booster assembly with master cylinder. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
LSB000824Status unverified
Brake, ABS and/or TRAC lights or Check VSC with C1391, C1252, C1253 or C1256
2014–2017ct · issued · NHTSA 10252263
2014–2017 CT 200h. Repair procedure for a small internal brake fluid leak inside the brake actuator. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
JeepYour car
2018–2026 · Wrangler
Supported by vehicle dataFCA S1805000006 covers the ESC light with C1252-92 vacuum pump control circuit or P258B on the Wrangler, and the revision extends it to 2026 and the Wrangler 4xe. The Cherokee and Gladiator are also covered. The bulletins are on NHTSA, but whether they are still current is not verified, so it is labelled vehicle data rather than confirmed.
Where it is:Electric vacuum pump
S1805000006Status unverified
ESC light on with C1252-92 vacuum pump control circuit and/or P258B electronic vacuum pump performance
2017–2020cherokee, wrangler, gladiator · issued · NHTSA 10173320
Covers the ESC light with C1252-92 or P258B on 2017–2020 Chrysler Pacifica, Jeep Cherokee, Wrangler and Gladiator, and 2019–2020 Ram 1500 in the cache. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
S1805000006 REV.BStatus unverified
ESC light on with C1252-92 vacuum pump control circuit and/or P258B electronic vacuum pump performance
2019–2026cherokee, wrangler, gladiator · issued · NHTSA 11025508
Revised version covering 2019–2023 Jeep Cherokee, 2019–2026 Wrangler and Wrangler 4xe, 2020–2026 Gladiator and 2019–2026 Ram 1500. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
RamYour car
2019–2026 · 1500
Supported by vehicle dataThe same FCA bulletin lists the 2019 and later Ram 1500 for C1252-92 with the ESC light. The bulletins are on NHTSA, but whether they are still current is not verified, so it is labelled vehicle data rather than confirmed.
Where it is:Electric vacuum pump
S1805000006Status unverified
ESC light on with C1252-92 vacuum pump control circuit and/or P258B electronic vacuum pump performance
2017–2020cherokee, wrangler, gladiator · issued · NHTSA 10173320
Covers the ESC light with C1252-92 or P258B on 2017–2020 Chrysler Pacifica, Jeep Cherokee, Wrangler and Gladiator, and 2019–2020 Ram 1500 in the cache. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
S1805000006 REV.BStatus unverified
ESC light on with C1252-92 vacuum pump control circuit and/or P258B electronic vacuum pump performance
2019–2026cherokee, wrangler, gladiator · issued · NHTSA 11025508
Revised version covering 2019–2023 Jeep Cherokee, 2019–2026 Wrangler and Wrangler 4xe, 2020–2026 Gladiator and 2019–2026 Ram 1500. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
ChryslerYour car
2017–2020 · Pacifica
Supported by vehicle dataThe original FCA bulletin lists the 2017–2020 Pacifica for C1252-92 with the ESC light. The bulletin is on NHTSA, but whether it is still current is not verified, so it is labelled vehicle data rather than confirmed.
Where it is:Electric vacuum pump
S1805000006Status unverified
ESC light on with C1252-92 vacuum pump control circuit and/or P258B electronic vacuum pump performance
2017–2020cherokee, wrangler, gladiator · issued · NHTSA 10173320
Covers the ESC light with C1252-92 or P258B on 2017–2020 Chrysler Pacifica, Jeep Cherokee, Wrangler and Gladiator, and 2019–2020 Ram 1500 in the cache. Only the NHTSA flat-file summary was reviewed, not the bulletin itself.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
Related codes
C1252 questions
Is it safe to drive with C1252?
If the red brake warning light is on, Toyota and FCA both say to stop and have it checked immediately. With only the ABS, TRAC or ESC lights, have it inspected right away.
Is C1252 covered by Toyota?
Customer Support Program 24TE01 covers the brake booster and booster pump on certain 2014–2016 Highlander hybrids and 2017 Prius v, verified by this group of codes. Ask a dealer to check your VIN.
Why are C1391, C1252, C1253 and C1256 often stored together?
Toyota's bulletins list all four for the same condition: a small internal brake fluid leak in the brake booster or brake actuator on hybrid models.
Does C1252 mean the same thing on a Jeep or Ram?
No. FCA uses C1252-92 for a vacuum pump control circuit fault, with the ESC light on, on models such as the Wrangler, Gladiator, Cherokee, Pacifica and Ram 1500.
Sources and review
- Toyota Camry Owner's Manual (OM06291U)
- Toyota T-SB-0024-19: brake, ABS, TRAC lights or Check VSC with C1391/C1252/C1253/C1256 (Prius, Prius Plug-in)
- Toyota T-SB-0032-16: brake, ABS, TRAC lights or Check VSC with C1391/C1252/C1253/C1256 (Prius, Highlander HV)
- FCA S1805000006: ESC light on, C1252-92 vacuum pump control circuit and/or P258B electronic vacuum pump performance
- 2022 Ram 2500/3500 Owner's Manual: ESC Activation/Malfunction Indicator Light
- 2022 Ram 2500/3500 Owner's Manual: Brake Warning Light
- Prius Code Troubleshooting Guide
- Toyota Customer Support Program 24TE01: brake booster and brake booster pump assemblies
- Small Brake Fluid Leak for Toyota
- Toyota T-SB-0089-20: brake, ABS, TRAC lights or Check VSC with C1391/C1252/C1253/C1256 (Prius v)
- Toyota T-SB-0115-20: brake, ABS, TRAC lights or Check VSC with C1391/C1252/C1253/C1256 (2015 Prius v)
- Toyota T-SB-0013-23: brake, ABS, TRAC lights or Check VSC with C1391/C1252/C1253/C1256 (Prius v)
- Toyota T-SB-0028-21: brake, ABS, TRAC lights or Check VSC with C1391/C1252/C1253/C1256 (Prius c)
- Toyota T-SB-0130-19: brake, ABS, TRAC lights or Check VSC with C1391/C1252/C1253/C1256 (Camry Hybrid, Avalon Hybrid)
- Lexus L-SB-0009-21: brake, ABS, TRAC lights or Check VSC with C1391/C1252/C1253/C1256 (CT 200h)
- Toyota T-SB-0064-19: brake, ABS, TRAC lights or Check VSC with C1391/C1252/C1253/C1256 (Highlander Hybrid)
- Toyota T-SB-0041-14: brake, ABS, TRAC lights or Check VSC with C1391/C1252/C1253/C1256 (Camry HV)
- Toyota TSB000824: brake, ABS, TRAC lights or Check VSC with C1391/C1252/C1253/C1256 (Prius c)
- Toyota TSB000924: brake, ABS, TRAC lights or Check VSC with C1391/C1252/C1253/C1256 (Highlander Hybrid)
- Toyota T-SB-0014-25: brake, ABS, TRAC lights or Check VSC with C1391/C1252/C1253/C1256 (Highlander Hybrid)
- Lexus LSB000824: brake, ABS, TRAC lights or Check VSC with C1391/C1252/C1253/C1256 (CT 200h)
- FCA S1805000006 REV.B: ESC light on, C1252-92 vacuum pump control circuit and/or P258B electronic vacuum pump performance
- Last reviewed
- Written by
- Saurabh K.
- Editorial review
- Pending
- Technician review
- Technician review pending
This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error