Circuit Description
The electronic ignition system uses an individual ignition coil for each cylinder. The powertrain control module (PCM) controls the ignition operation through eight individual ignition control (IC) circuits. Each bank of four ignition coils is connected to the PCM, power, or ground by the following circuits:
| • | Low reference |
| • | Chassis ground |
| • | Ignition 1 voltage |
| • | The appropriate IC circuit |
The PCM triggers an ignition coil by grounding the appropriate IC circuit using information from the crankshaft position (CKP) and camshaft position (CMP) sensors.
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views | ||||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||||
2 |
Does the scan tool display engine RPM? | -- | Go to Step 3 | Go to Step 13 | ||||||
3 | Is DTC P0335, P0336, or P0351-P0358 also set? | -- | Go to Step 4 | |||||||
Does the scan tool display any misfire current counters incrementing? | -- | Go to Step 5 | Go to Intermittent Conditions | |||||||
5 |
Do you have bright blue spark on the cylinders? | -- | Go to Step 6 | Go to Step 7 | ||||||
6 |
Are the spark plugs in good condition? | -- | System OK | Go to Step 22 | ||||||
7 | Measure the spark plug wire resistance. Refer to Spark Plug Wire Inspection . Is the resistance more than the specified value? | 700 ohms/ft | Go to Step 23 | Go to Step 8 | ||||||
8 |
Does the test lamp illuminate? | -- | Go to Step 9 | Go to Step 19 | ||||||
9 | Probe the ignition voltage circuit at the affected ignition coil with a test lamp that is connected to the ground circuit of the affected ignition coil. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate? | -- | Go to Step 10 | Go to Step 20 | ||||||
10 | Probe the ignition voltage circuit at the affected ignition coil with a test lamp that is connected to the low reference circuit of the affected ignition coil. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate? | -- | Go to Step 11 | Go to Step 15 | ||||||
11 | Measure the resistance of the ignition voltage circuit of the affected ignition coil from the fuse that supplies ignition voltage to the affected ignition coil to the harness connector of the affected ignition coil. Is the resistance less than the specified value? | 3 ohms | Go to Step 12 | Go to Step 19 | ||||||
12 | Measure the resistance of the ground circuit of the affected ignition coil from the harness connector of the affected ignition coil to a good ground. Is the resistance less than the specified value? | 3 ohms | Go to Step 17 | Go to Step 20 | ||||||
13 |
Is the difference in the voltage more than the specified value? | 0.5 V | Go to Step 14 | Go to Step 16 | ||||||
14 | Test for a short to ground in the CKP 12-volt reference circuit or the camshaft position (CMP) sensor 12-volt reference circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 26 | Go to Step 18 | ||||||
15 | Test the low reference circuit of the ignition coil for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 26 | Go to Step 18 | ||||||
16 | Test for shorted terminals and poor connections at the CKP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 26 | Go to Step 21 | ||||||
17 | Test for an intermittent and for a poor connections at the ignition coil. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 26 | Go to Step 24 | ||||||
18 | Test for shorted terminals and for poor connections at the powertrain control module (PCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 26 | Go to Step 25 | ||||||
19 | Repair the ignition voltage circuit of the affected ignition coil for one of the following conditions:
Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 26 | -- | ||||||
20 | Repair the ground circuit of the affected ignition coil for one of the following conditions:
Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 26 | -- | ||||||
21 | Replace the CKP sensor. Refer to Crankshaft Position Sensor Replacement . Did you complete the replacement? | -- | Go to Step 26 | -- | ||||||
22 | Replace the spark plug. Refer to Spark Plug Replacement . Did you complete the replacement? | -- | Go to Step 26 | -- | ||||||
23 | Replace the spark plug wire. Refer to Spark Plug Wire Replacement . Did you complete the replacement? | -- | Go to Step 26 | -- | ||||||
24 | Replace the ignition coil. Refer to Ignition Coil Replacement . Did you complete the replacement? | -- | Go to Step 26 | -- | ||||||
25 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | Go to Step 26 | -- | ||||||
26 |
Does the vehicle operate normally? | -- | System OK | Go to Step 3 | ||||||
