TEST 2: Testing The Continuity Of The Idle Circuit

Testing The Continuity Of The Throttle Valve Switch Idle Circuit (2.6L Isuzu Pick Up, Rodeo, Amigo, 2.6L Honda Passport)

Continuity should exist between two specific pins of the throttle valve (TV) switch when the throttle plate is closed (and if the throttle valve switch is working correctly and adjusted correctly).

Once the throttle plate opens (like when you step on the accelerator pedal), this circuit opens and loses continuity.

When this doesn't happen (either because the TV switch is bad or mis-adjusted), the fuel injection computer, on your 2.6L Isuzu Rodeo (Amigo, Pick Up), will usually set a trouble code 43: Throttle Valve Switch (Idle Position).

So, in this second test, we're gonna' check this ‘idle’ circuit with a multimeter in Ohms mode.

OK, these are the test steps:

  1. 1

    Disconnect the throttle valve switch from its connector.

    NOTE: Use the illustration above to identify the correct pins to test on the throttle valve switch itself.

  2. 2

    Set your multimeter to Ohms (Ω) mode and make sure that the throttle plate, in the throttle boy, is in the closed position.

  3. 3

    With the throttle plate closed, measure the resistance across pin #1 and pin #2 of the throttle valve (TV) switch as shown in the illustration above.

    Your multimeter should show continuity (usually 5 Ohms or less).

  4. 4

    Open the throttle plate to its fully open position and measure the resistance of pins #1 and pin #2 again.

    Your multimeter SHOULD NOT register continuity (it should register OL).

  5. 5

    Repeat steps 3 through 4 several times just to make sure of your test results.

Let's find out what your specific multimeter test results mean:

CASE 1: Your multimeter registered the indicated continuity test results. This confirms that the ‘idle’ circuit of the throttle switch is OK.

Your next step is to check the ‘Wide Open Throttle (WOT)’ circuit of the throttle valve switch. Go to: TEST 3: Testing The Continuity Of The WOT Circuit.

CASE 2: Your multimeter DID NOT register the indicated continuity test results. This tells you that the ‘idle’ switch part of the throttle valve switch is defective. Replace the throttle valve switch

Before replacing the throttle valve switch, I suggest that you make sure that its not mis-adjusted. For this procedure, go to: Adjusting the Throttle Valve Switch.

TEST 3: Testing The Continuity Of The WOT Circuit

Testing The Continuity Of The Throttle Valve Switch WOT Circuit (2.6L Isuzu Pick Up, Rodeo, Amigo, 2.6L Honda Passport)

If you've reached this point, you have: 1) Confirmed the throttle valve switch is getting power (TEST 1). 2) Confirmed that the ‘idle’ circuit of the TV switch is OK (TEST 2).

We are now gonna' check that the throttle valve (TV) switch's ‘Wide Open Throttle’ circuit is OK.

Testing the WOT circuit follows pretty much the same type of continuity tests you performed in TEST 2.

These are the test steps:

  1. 1

    Disconnect the throttle valve switch from its connector and set your multimeter's function to Ohms mode.

    NOTE: Use the illustration above to identify the correct pins to test on the throttle valve switch itself.

  2. 2

    With the throttle plate in its fully open position, measure the resistance across pin #2 and pin #3 of the throttle valve (TV) switch as shown in the illustration above.

    Your multimeter should show continuity (usually 5 Ohms or less).

  3. 3

    With the throttle plate in its closed position measure the resistance of pins #2 and pin #3 again.

    Your multimeter SHOULD NOT register continuity (it should register OL).

  4. 4

    Repeat steps 2 through 3 several times just to make sure of your test results.

Let's find out what your specific multimeter test results mean:

CASE 1: Your multimeter registered the indicated continuity test results. This confirms that the ‘WOT’ circuit of the throttle switch is OK.

CASE 2: Your multimeter DID NOT register the indicated continuity test results. This tells you that the ‘WOT’ switch part of the throttle valve switch is defective. Replace the throttle valve switch.

Before replacing the throttle valve switch, I suggest that you make sure that its not mis-adjusted. For this procedure, go to: Adjusting the Throttle Valve Switch.

Isuzu Vehicles:

  • Amigo 2.6L
    • 1993, 1994
  • Pick Up 2.6L
    • 1993, 1994, 1995
  • Rodeo 2.6L
    • 1993, 1994, 1995, 1995