Are you having trouble starting your Toyota in the morning? We have been there and know how frustrating that feeling can be. Early in the morning what you need to worry about getting to work, the last thing you need is your daily driver cranking forever without starting, finally, if you are lucky enough you didn't drain all your battery's juice it will end up starting, PITA isn't it? That why we decided to show you how to test both your Cold Start Injector and your Cold Start Time Switch (this switch tells the injector when to spray that extra fuel in order to make it easier to start your vehicle on colder weather) this way you could get rid of your every morning starting problems.


    Cold Start Time Switch

    This Time Switch tells the Cold Start Injector when to fire. It is located under the throttle body on the lower intake manifold, right next to the ECU coolant temperature sensor (not the gauge temperature sensor). The CSITS is the one with the brown plug(or black in the newer 22RE models), it usually is the one on the left side from the green plug.


    1. 1.-Disconnect the battery ground cable.
    2. 2.-Disconnect the wire harness from the cold start injector time switch (located in the thermostat housing on the 4cyl models and in the water bypass outlet at the rear of the intake manifold on the V6 models.
    3. 3.-Using an ohmmeter, measure the resistance between the terminals as shown in the accompanying tables (see illustrations).
    4. 4.-If the resistance readings do not fall within the specified range, the cold start injector time switch will have to be replaced.
    5. 5.-To replace the star injector time switch, drain the coolant, unplug the switch electrical connector and unscrew the switch. Be sure to coat the threads of the new switch with Teflon tape to prevent leaks. Installation in the reverse of removal.


    Cold Start Injector

**Note: Because of the special tools required to test the cold start injector off the vehicle, it is recommended that it be done by a Toyota dealer service department. The procedure described below in an on vehicle check of the cold start injector. If the test results are inconclusive, have the system checked by a dealer service department.**

The Cold Start Injector is the responsible for supplying more fuel into the intake manifold for an easier start on cold temperatures. It is located in the middle of the upper intake manifold plenum.

Check: (**This check must be done with the engine cold.**)

  1. 1.-Start the engine and, using the procedure described in section 20, listen to the cold start injector (located on the air intake chamber). You should hear a clicking noise, meaning the injector is functioning.
  2. 2.-If a clicking sound is heard, let the engine reach operating temperature and repeat the check. No clicking should be heard.
  3. 3.-If no clicking is heard in Step 2, a resistance check of the cold start injector should be performed. To do this, turn the ignition switch to the Off position.
  4. 4.-Disconnect the battery ground cable.
  5. 5.-Disconnect the wire harness from the cold start injector.
  6. 6.-Using an ohmmeter, measure the resistance between the injector terminals. It should be 2 to 4 ohms. If the resistance is not as specified, the injector is most likely defective. Further testing is beyond the scope of the home mechanic. Remove the injector and have it bench-tested by a Toyota dealer.


If both, your Injector and the Time Switch tested good and you still have problems starting your vehicle, we would recommend taking a closer look at these:

  • Fuel Pressure Regulator
  • Fuel Pump & Filter (Gas Cap too, YES! Gas Cap)
  • Ignition Switch (on the the steering column, it's a common issue)
  • Starter
  • Battery
  • Wiring (grounds and condition of the wiring)
  • Spark Plug Wires
  • Ignition System


We hope this Tech Note Helps you, if you have any questions please contact our super cool staff 877-505-2501 or 928-855-6341






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