P3191 On Toyota hybrids, the engine did not start when the hybrid system asked it to

Toyota Prius P3191: engine does not start

P3191 in short

On Toyota hybrids, P3191 means the engine did not start when the hybrid system asked it to. Toyota bulletins tie it, with P0A0F and P3190, to a separated purge valve line on the 2010-2013 Prius and to engine computer updates. A weak 12-volt battery or a dirty throttle body are other causes. Get it checked soon.

A Toyota hybrid starts its gasoline engine with the electric motor-generator. If the engine does not catch, the hybrid computer stores P3191 (engine does not start), often with P3190 (poor engine power) and P0A0F (engine failed to start), and lights the master and hybrid warning lamps.

Toyota bulletin T-SB-0041-15 says on 2010-2013 Prius and 2012-2013 Prius v the purge VSV/PCV line can separate from the throttle body and set P0A0F, with P3190, P3191 and P0171 possible; the fix replaces the purge VSV and reprograms the engine computer. Lexus L-SB-0019-15 covers the CT 200h. Bulletin 0205-11 revises engine computer logic for 2010-2011 Prius, and older 2001-2005 Prius bulletins also list the code.

A shop reference for the 2001-2009 Prius lists a worn or reset 12-volt battery, throttle body varnish, a dirty air flow sensor and, on 2001-2003 cars, a weak fuel pump. It warns that repeated start attempts can drain the hybrid battery.

The engine start system runs through the hybrid system. Diagnosis beyond reading codes belongs with a dealer or hybrid-trained technician.

Pick your make

P3191 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

  1. Purge VSV/PCV line separated from the throttle body (2010-2013 Prius, Prius v, CT 200h)

    Supported by vehicle data
    Why it ranks here
    Toyota T-SB-0041-15 and Lexus L-SB-0019-15 name this for P0A0F with P3190 and P3191 as possible companions, with a purge VSV replacement and engine computer update.
    What would change this
    Rises on a covered 2010-2013 Prius, Prius v or CT 200h with P0A0F stored. Falls on other models or if the line is attached.
    How to test the evap canister purge valve

  2. Engine computer logic that needs an update (2010-2011 Prius)

    Supported by vehicle data
    Why it ranks here
    Toyota bulletin 0205-11 revises engine computer logic for P0A0F, P3190 and P3191 on 2010-2011 Prius.
    What would change this
    Rises if the engine computer is not at the latest calibration. Falls if it is current.
    How to test the engine control module (ecm / pcm)

  3. 12-volt battery reset or weak, dirty throttle body or air flow sensor

    Common general cause
    Why it ranks here
    The shop reference lists a worn or reset 12-volt battery, throttle body varnish and a dirty air flow sensor as common causes on the 2001-2009 Prius, since the engine will not start without enough air.
    What would change this
    Rises if the 12-volt battery was recently replaced or disconnected, or the throttle body is dirty. Falls if both are in good shape.
    How to test the electronic throttle body

  4. Weak fuel pump (2001-2003 Prius)

    Possible — needs testing
    Why it ranks here
    The shop reference lists the pump as common on 2001-2003 cars; it is one reference, not a maker finding.
    What would change this
    Rises on a 2001-2003 Prius with low fuel pressure. Falls on later models or good pressure.
    How to test the fuel pump

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Read all stored codes and note whether P0A0F, P3190 or P0171 are stored too. Avoid repeated start attempts, which can drain the hybrid battery.

    Low riskTool: OBD-II scan tool

  2. Ask a Toyota or Lexus dealer to check the VIN for the purge VSV bulletin and engine computer updates.

    Low riskTool: VIN lookup at a dealer

Symptoms

  • Master, hybrid and check engine warning lights
  • Engine will not start or stalls Gets more serious: stop and have it checked.
  • Poor engine power

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

  • Purge VSV (Toyota):Replaced with an engine computer update under T-SB-0041-15 on covered 2010-2013 Prius. Labor varies; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Toyota

  • 2001–2013 · Prius

    Supported by vehicle data

    Prius: Toyota bulletins list P3191 with P3190 and P0A0F from 2001; on 2010-2013 cars the purge VSV/PCV line separation and engine computer updates apply.

  • 2012–2013 · Prius V

    Supported by vehicle data

    Prius v: same purge line bulletin as the Prius.

  • 01202Status unverified

    Master, hybrid and MIL lamps on with P3190, P3191 and P3101

    2001–2002prius · issued · NHTSA 635855

    Title-level summary only for the 2001-2002 Prius.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • 01103Status unverified

    Master, hybrid and MIL lamps on with P3190, P3191 and P3101

    2001–2003prius · issued · NHTSA 10003359

    Title-level summary only; updated 2007.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • 02704Status unverified

    MIL on with P3191, P3190 and/or P0A0F

    2004–2005prius · issued · NHTSA 10010308

    Title-level summary; supersedes EG027-04.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • TSB-0205-11REV-1Status unverified

    Engine computer logic revision for P0A0F, P3190 and P3191

    2010–2011prius · issued · NHTSA 10044581

    Revises engine control module logic to address these codes.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • T-SB-0041-15Status unverified

    P0A0F with P3190, P3191 and P0171: purge VSV/PCV line separation

    2010–2013prius, prius-v · issued · NHTSA 10111144

    Replace the purge VSV and reprogram the engine computer.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Lexus

  • L-SB-0019-15Status unverified

    P0A0F with possible P3190 and P3191 on CT 200h

    2011–2013ct · issued · NHTSA 10111152

    Same purge VSV/PCV line condition as T-SB-0041-15.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • P3190Poor engine power on Toyota and Lexus hybrids

    Shares causes Supported by vehicle data

    Toyota bulletins list P3191 with P3190 (poor engine power) and P0A0F for the same purge VSV/PCV line and engine computer fixes.

All Hybrid and electric drive codes

P3191 questions

Is P3191 the same on every Toyota?

We confirmed the meaning on Prius, Prius v and, through Lexus, the CT 200h hybrids. Other Toyota models are not covered here.

Can I keep trying to start the car?

Avoid it. Repeated attempts can drain the hybrid battery and make the problem worse.

Sources and review

  1. T-SB-0041-15: P0A0F with P3190 and P3191 on Prius and Prius v — Toyota Motor Sales
  2. TSB-0205-11 Rev 1: P0A0F, P3190 and P3191 engine computer logic — Toyota Motor Sales
  3. 2001-2009 Prius P3191, P3190, P0A0F quick checks — CarSpecMN
  4. L-SB-0019-15: P0A0F on the CT 200h — Lexus
  5. TSB 01103: master, hybrid and MIL lamps with P3190, P3191 and P3101 — Toyota Motor Sales
  6. TSB 02704: MIL with P3191, P3190 and/or P0A0F — Toyota Motor Sales
Last reviewed
Written by
Saurabh K.
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