This tutorial will walk you through the ignition coil testing process step-by-step on the 4.2L Oldsmobile Bravada and 4.2L Buick Rainier.
With your test results you'll quickly determine if an ignition coil has failed and is causing a misfire problem (and misfire trouble code).
Contents of this tutorial:
- Symptoms Of A Bad Ignition Coil.
- Ignition Coil Pin Outs.
- Where To Buy The Ignition Coil And Save.
- TEST 1: Testing The Ignition Coil For Spark.
- TEST 2: Making Sure The Ignition Coil Is Getting Power.
- TEST 3: Making Sure The Ignition Coil Is Getting Ground.
- TEST 4: Swapping The Ignition Coils.
- Other Common Misfire Causes.
- More 4.2L Oldsmobile Bravada And Buick Rainier Tutorials.
APPLIES TO: This tutorial applies to the following vehicles:
- 4.2L Buick Rainier: 2004, 2005, 2006, 2007.
- 4.2L Oldsmobile Bravada: 2002, 2003, 2004.
Symptoms Of A Bad Ignition Coil
As you're already aware, the ignition coil is the component that creates and delivers the spark to the spark plug.
The spark plug then channels the spark into the cylinder, igniting the air/fuel mixture.
When the ignition coil fails and stops creating spark, the cylinder (the ignition coil is connected to) will misfire.
You'll see the fuel injection computer set one or more of the following misfire diagnostic trouble codes:
- P0300: Random Cylinder Misfire.
- P0301: Cylinder #1 Misfire.
- P0302: Cylinder #2 Misfire.
- P0303: Cylinder #3 Misfire.
- P0304: Cylinder #4 Misfire.
- P0305: Cylinder #5 Misfire.
- P0306: Cylinder #6 Misfire.
Besides a misfire trouble code stored in your Buick Rainier or Oldsmobile Bravada's fuel injection computer, you're going to see one or more of the following symptoms:
- Bad fuel mileage.
- The check engine light flashes when the misfire is occurring.
- Rough idle.
- Lack of power as you accelerate under load.
- Engine misses (misfires) as you accelerate it's under load.
- Smell of raw fuel coming out of the tailpipe.
Ignition Coil Pin Outs
| Ignition Coil -Cyl #1 | ||
|---|---|---|
| A | Pink (PNK) | 12 Volts |
| B | Purple (PPL) | Activation Signal |
| C | Black (BLK) | Chassis Ground |
| Ignition Coil -Cyl #2 | ||
|---|---|---|
| A | Pink (PNK) | 12 Volts |
| B | Red with white stripe (RED/WHT) | Activation Signal |
| C | Black (BLK) | Chassis Ground |
| Ignition Coil -Cyl #3 | ||
|---|---|---|
| A | Pink (PNK) | 12 Volts |
| B | Light Blue (LT BLU) | Activation Signal |
| C | Black (BLK) | Chassis Ground |
| Ignition Coil -Cyl #4 | ||
|---|---|---|
| A | Pink (PNK) | 12 Volts |
| B | Dark green with white stripe (DK GRN/WHT) | Activation Signal |
| C | Black (BLK) | Chassis Ground |
| Ignition Coil -Cyl #5 | ||
|---|---|---|
| A | Pink (PNK) | 12 Volts |
| B | Dark green (DK GRN) | Activation Signal |
| C | Black (BLK) | Chassis Ground |
| Ignition Coil -Cyl #6 | ||
|---|---|---|
| A | Pink (PNK) | 12 Volts |
| B | Light blue with white stripe (LT BLU/WHT) | Activation Signal |
| C | Black (BLK) | Chassis Ground |
Where To Buy The Ignition Coil And Save
The following links will help you to comparison shop for the ignition coil. All of the links point to well-known automotive brand ignition coils (no knock-offs):
TEST 1: Testing The Ignition Coil For Spark
I'm going to recommend that you test all six ignition coils for spark.
It's important you use a dedicated spark tester to test the ignition coils for spark.
Any other method of testing the ignition coils for spark may give you a false test result, which may have you wasting time and money.
If you don't have a spark tester, check my recommendation here: The HEI Spark Tester (The Best Spark Tester On The Market).
These are the test steps:
- 1
Remove the ignition coil from its place on the valve cover.
- 2
Connect your spark tester to the ignition coil.
- 3
Reconnect the ignition coil to its electrical connector (if you disconnected it to remove it).
- 4
Ground the spark tester with a battery jump start cable directly on the battery negative (-) terminal.
- 5
Have a helper crank the engine while you observe the spark tester.
- 6
The spark tester will do one of two things: Spark or Not Spark.
- 7
Repeat steps 1 thru' 6 on the remaining ignition coils.
Let's take a look at what your test results mean:
CASE 1: All six ignition coils sparked. This is the correct and expected test result.
This test result also confirms the ignition coils are receiving power, Ground, and an activation signal.
If a cylinder is misfiring, take a look at the following section for more testing suggestions: Other Common Misfire Causes.
CASE 2: One or more ignition coils DID NOT spark. This test result generally lets you know that the ignition coil (that is not sparking) is defective and needs to be replaced.
Before condemning the ignition coil as defective, make sure that it's getting power, Ground and an activation signal. Go to: TEST 2: Making Sure The Ignition Coil Is Getting Power.
