The ignition control module (ICM) has independent power and ground circuits. The circuits between the ICM and the powertrain control module (PCM) consists of the following circuits:
• | The ignition control (IC) timing signal |
• | The IC timing control |
• | The low resolution engine speed signal |
• | The medium resolution engine signal |
• | The camshaft position signal |
• | The low reference |
For a complete system description, refer to Electronic Ignition (EI) System Description .
Step | Action | Values | Yes | No | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module Connector End Views | ||||||||||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||||||||||
2 | Attempt to start the engine. Does the engine start and run? | -- | Go to Step 5 | Go to Step 3 | ||||||||||||
3 |
Does the scan tool indicate RPM is present? | -- | Go to Step 4 | |||||||||||||
4 |
Is the frequency more than the specified value? | 0 Hz | Go to Step 5 | |||||||||||||
5 |
Important: Ground the companion cylinder of the cylinder being tested. Did you have spark on any of the cylinders? | -- | Go to Step 6 | Go to Step 14 | ||||||||||||
6 | Did you have spark on all of the cylinders? | -- | Go to Step 7 | Go to Step 9 | ||||||||||||
7 | Does the spark tester indicate a bright blue spark on all cylinders? | -- | Go to Step 8 | Go to Step 9 | ||||||||||||
8 |
Are the spark plugs in good condition? | -- | System OK | Go to Step 15 | ||||||||||||
9 |
Do you have spark on the inoperative cylinder? | -- | Go to Step 12 | Go to Step 10 | ||||||||||||
10 |
Is the resistance within the specified range? | 5,000-8,000 ohms | Go to Step 11 | Go to Step 17 | ||||||||||||
11 |
Does the test lamp turn ON and OFF while the engine is being cranked? | -- | Go to Step 13 | Go to Step 14 | ||||||||||||
12 | Test the spark plug wires for the following:
Did you find and correct the condition? | -- | Go to Step 19 | Go to Step 16 | ||||||||||||
13 | Test for an intermittent and for a poor connection at the ignition coil. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 19 | Go to Step 17 | ||||||||||||
14 | Test for an intermittent and for a poor connection at the ICM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 19 | Go to Step 18 | ||||||||||||
15 | Replace the spark plugs. Refer to Spark Plug Replacement . Did you complete the replacement? | -- | Go to Step 19 | -- | ||||||||||||
16 | Replace the spark plug wires. Refer to Spark Plug Wire Replacement . Did you complete the replacement? | -- | Go to Step 19 | -- | ||||||||||||
17 | Replace the ignition coil. Refer to Ignition Coil Replacement . Did you complete the replacement? | -- | Go to Step 19 | -- | ||||||||||||
18 | Replace the ICM. Refer to Ignition Control Module Replacement . Did you complete the replacement? | -- | Go to Step 19 | -- | ||||||||||||
19 |
Does the vehicle operate normally? | -- | System OK | Go to Step 1 |