P1604Manufacturer-specific code

P1604 Code: Engine Startability Malfunction (Toyota)

On Toyota and Lexus vehicles, the P1604 code means a startability malfunction: the engine takes a long time to start or will not start. It does not point to one part. It tells you something is preventing a normal start.

Severity
Medium
Can I keep driving?
Yes, but with caution
Estimated cost
$0 to $700
Difficulty
Medium
System
Computer and Outputs
Applies to
Depends on the manufacturer

Common in: Toyota

Updated Reviewed by Renzo Chacca

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What the P1604 code means

P1604 is a manufacturer-specific code: the 1 in the second position means each automaker defines what it means, not the generic SAE standard. The most widespread definition is the one used by Toyota and Lexus. If your vehicle is another brand, confirm the code text with a scan tool that supports that manufacturer.

ManufacturerMeaning of P1604
Toyota and LexusStartability malfunction (engine slow to start or will not start)

Toyota sets the P1604 code when the engine turns over with the starter but takes too long to fire. It does not name a part: it says something is preventing a normal start.

It often comes with other codes, such as crankshaft or camshaft sensor codes, which point toward the cause.

Before you start repairs, confirm the make, model, year and engine. With manufacturer codes, the same number can change even between engines from the same brand.

P1604 code symptoms

  • Long or hard starting.
  • The engine stalls shortly after starting.
  • Check engine light on.

Likely causes of the P1604 code

  1. Low fuel pressure. Check the pump, the filter and the regulator.
  2. Weak battery. The engine cranks slowly.
  3. Crankshaft or camshaft sensor. Confirm it by comparing its reading with the real value.
  4. Dirty throttle body. Confirm it with the tests in the diagnosis section.
  5. Immobilizer, if it does not recognize the key.

How to diagnose the P1604 code step by step

  1. Read the other codes stored with it.
  2. Measure the fuel pressure.
  3. Test the battery and the starter.
  4. Check the immobilizer light.

How to fix the P1604 code

  • Repair the cause the other codes point to.
  • Replace the pump or the filter if the pressure is low.
  • Clean the throttle body.

Technical reference data

  • Typical fuel pressure: about 3 to 3.5 bar (roughly 44 to 51 psi) on many port-injected Toyotas.
  • P1xxx codes are manufacturer-specific: confirm the definition with a scan tool that supports your brand.
  • Reference values: check the manufacturer data for your vehicle.

Brand-specific notes

Read every code stored with this one. The companion codes usually tell you where to look, because this one only says the start was poor.

P1604 on Toyota

Common on the Corolla, Camry and Tacoma.

If your vehicle is another brand, check the table above for the meaning its manufacturer gives this code and confirm it with a compatible scan tool.

Frequently asked questions about P1604

What does the P1604 code mean on a Toyota?
It means a startability malfunction: the engine takes a long time to start or will not start at all.
Does P1604 mean the same thing on every brand?
No. It is a manufacturer-specific code, so on other brands it may not exist or may mean something different. Confirm it with a scan tool that supports your make.
Can I drive with a P1604 code?
Yes, if it starts, but with caution. A P1604 code can leave you stranded the next time you try to start the engine.
How much does it cost to fix P1604?
Roughly $0 to $700 on a Toyota. The cost depends on the cause, from a cleaning to a new fuel pump.
Will a P1604 code clear itself?
Not while the starting problem is still there. Find the cause, repair it, then clear the code and confirm the engine starts normally.
What is the most common cause of P1604?
Low fuel pressure and a weak battery are the usual suspects. A crankshaft or camshaft sensor, a dirty throttle body and the immobilizer come next.

Related codes

Questions about the P1604 code

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