Bench-Testing The CMP Sensor (1999-2006 V8 Silverado, Sierra, Suburban, Tahoe, Yukon)

TEST 2: Using A Magnet To Induce The CMP Signal

Now that we've made all of the connections, we're now gonna' use a magnet to induce the CMP sensor to produce its signal voltage.

I recommend that you use a telescoping magnet, like the one I'm using in the photo, for this test.

OK, let's get started:

1. 1

   Observe the state of the LED light. Is the LED light ON or is it OFF?
   
   Whatever state it is in (ON or OFF), this is your base reading.

2. 2

   Rotate the telescoping magnet around the base of the CMP sensor.
   
   You can rotate the magnet in a clockwise or counter-clockwise direction.
   
   NOTE: Rotate the magnet as close to the base of the CMP sensor as possible but without letting it make physical contact.

3. 3

   The LED light should blink ON and OFF as you rotate the magnet around the base of the CMP sensor (if the sensor is good).
   
   NOTE: Depending on the rotation of the magnet (clockwise or counter-clockwise), the LED light will blink ON and OFF or OFF and ON.

Let's interpret your test results:

CASE 1: The LED light blinked ON and OFF (or OFF and ON). This is the correct test result and it lets you know that the CMP sensor is functioning correctly.

CASE 2: The LED light DID NOT blink ON and OFF (or OFF and ON). Recheck your connections and try the test again.

If the LED light still does not blink ON and OFF (or OFF and ON), then you can conclude that the camshaft position (CMP) sensor is bad and needs to be replaced.

Cardboard Separator Dimensions

To make my cardboard separators, I use a very thin piece of cardboard (usually a discarded oil filter box). I've also used index cards.

More Chevrolet Silverado (GMC Sierra) Tutorials

You can find a complete list of V8 Chevrolet Silverado (GMC Sierra) tutorials in this index:

• GM 4.8L, 5.3L, 6.0L Index Of tutorials.

Here's a small sample of the tutorials you'll find in the index:

• Resistance Specifications Of The TAC Electronic Throttle Body.
• How To Test The GM Accelerator Pedal Position (APP) Sensor 2.
• How To Test The MAF Sensor (GM 4.8L, 5.3L, 6.0L, 8.1L).
• Blown Head Gasket Test (GM 4.8L, 5.3L, 6.0L).