Diagnostic Aids

WARNING: This page is about a different variant/trim than selected.

Perform the spark plug inspection procedure before continuing with this diagnostic. Refer to Spark Plug Inspection .

Electronic Ignition (EI) System Diagnosis

Step	Action	Values	Yes	No
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module (PCM) Connector End Views or Engine Controls Connector End Views
1	Did you perform the Diagnostic System Check - Vehicle?	-	Go to Step 2	Go to DIAGNOSTIC SYSTEM CHECK - VEHICLE
2	Turn OFF the ignition. Inspect the fuse that supplies ignition voltage to the ignition coil/modules. Is the fuse open?	-	Go to Step 9	Go to Step 3
3	Disconnect the harness connector of the affected ignition coil/module. Test for an intermittent and for a poor connection at the ignition coil/module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?	-	Go to Step 14	Go to Step 4
4	Turn ON the ignition, with the engine OFF. Measure the battery voltage with a DMM. Connect a test lamp from the ignition voltage circuit of the affected ignition coil/module to a good ground. With the test lamp connected, measure the voltage from the ignition voltage circuit to a good ground with a DMM. Does the voltage measure within 0.5 volt of the specified value?	B+	Go to Step 5	Go to Step 10
5	Turn OFF the ignition, and all electrical accessories and components. Allow sufficient time for the control modules to power down before taking a resistance measurement. Measure the resistance of the ground circuit of the affected ignition coil/module from the harness connector of the ignition coil/module to a good ground with a DMM. Is the resistance less than the specified value?	3 ohm	Go to Step 6	Go to Step 11
6	Exchange the affected ignition coil/module with one from a cylinder that is not misfiring. Start the engine. Observe the Misfire Data List with a scan tool. Does the misfire follow the transferred ignition coil/module?	-	Go to Step 12	Go to Step 7
7	Test the ignition control (IC) circuit of the affected ignition coil/module for the following conditions: A high resistance or an open A short to ground A short to voltage Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?	-	Go to Step 14	Go to Step 8
8	Test for an intermittent and for a poor connection at the powertrain control module (PCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?	-	Go to Step 14	Go to Step 13
9	Repair the short to ground in the spliced circuits or the ignition coil/module, as needed. Refer to Testing for Short to Ground and Wiring Repairs . Did you complete the repair?	-	Go to Step 14	-
10	Repair the high resistance or an open in the ignition voltage circuit of the affected ignition coil/module. Refer to Wiring Repairs . Did you complete the repair?	-	Go to Step 14	-
11	Repair the high resistance or an open in the ground circuit of the affected ignition coil/module. Refer to Wiring Repairs . Did you complete the repair?	-	Go to Step 14	-
12	Replace the ignition coil/module. Refer to Ignition Coil(s) Replacement . Did you complete the replacement?	-	Go to Step 14	-
13	Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement?	-	Go to Step 14	-
14	Turn the ignition OFF for 60 seconds. Start the engine and operate the vehicle. Observe the vehicle performance and driveability. Does the vehicle operate normally?	-	System OK	Go to Step 2