For 1990-2009 cars

Refer to Engine Controls Schematic

#### Power, Ground, KS,CMP,CKP,Coils, and ICM

Engine Controls Components
Electronic Ignition (EI) System Description
Power, Ground, and Injectors
Power, Ground, MIL, and DLC
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice
Power Distribution Schematics
Ground Distribution Schematics
.

### Circuit Description

This engine is equipped with a ignition system called the electronic ignition (EI) system. The primary circuit of the EI system consists of the following components:

• | Two separate ignition coils

• | The electronic ignition control module (ICM)

• | The crankshaft position (CKP) sensor

• | The related connecting wires and the ignition control portion of the PCM

Each secondary circuit consists of the following components:

• | The secondary winding of the coil

• | The 2 connecting metal strips molded into the coil housing

• | The spark plug boot/connector assemblies

• | The spark plugs

### Diagnostic Aids

• | A small amount of resistance in the battery positive voltage circuit to the PCM may cause a no-start. Test the B+ circuit for excessive resistance or corrosion. Refer to Wiring Repairs in Wiring Systems.

• | The PCM grounds will cause a no-start only if all of the grounds are not making a good connection. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

• | Inspect the throttle position (TP) sensor for the following conditions:

- | Any binding or sticking

- | An intermittent short

- | An intermittent open

- | Refer to DTC P0105 Manifold Absolute Pressure (MAP) Sensor Performance/Range .

• | The engine coolant temperature (ECT) sensor may be skewed within specifications and not set a code. On a cold vehicle the ECT and intake air temperature (IAT) should be within 3°C (5°F) of each other. For a hot vehicle, let the engine cool to the ambient temperature before performing the test.

• | The manifold absolute pressure (MAP) sensor may be skewed within specifications and not set a code. Refer to DTC P0105 Manifold Absolute Pressure (MAP) Sensor Performance/Range .

• | A loose crankshaft position (CKP) sensor may cause an intermittent no-start condition by moving away from the reluctor wheel. Verify that the sensor and the mating surface are clean and tight.

### Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. Verify that the fuel pump runs by removing the fuel cap and listening, or by feeling the fuel rail or fuel lines on key up.

2. Repair the cause of the malfunctioning Spark plugs before replacing.

3. Inspect for basic engine malfunction like low compression, burnt valves, worn timing chain and gears, etc.

4. A short to voltage in this step will read as a negative resistance.

5. Any time the CKP sensor is removed the Crankshaft Position Variation learn procedure must be performed.

6. The replacement PCM must be reprogrammed and the Crankshaft Position Variation learn procedure must be performed.

#### Engine Cranks But Will Not Run

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Powertrain On Board Diagnostic (OBD) System Check? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check
2 | Are DTCs P0601, P0602 or 1629 set? | -- | Go to Diagnostic Trouble Code (DTC) List/Type | Go to Step 3
3 |

1. Crank the engine.
2. Observe the CKP Activity Counter on the scan tool.

Does the CKP Activity Counter increment?

--

Go to Step 4

Go to Step 9

4 |

1. Turn ON the ignition, with the engine OFF.
2. With the scan tool, command the fuel pump ON.

Does the fuel pump run?

--

Go to Step 5

Go to Fuel Pump Electrical Circuit Diagnosis

5 |

1. Turn OFF the ignition.

Caution: Wrap a shop towel around the fuel pressure connection in order to reduce the risk of fire and personal injury. The towel will absorb any fuel leakage that occurs during the connection of the fuel pressure gage. Place the towel in an approved container when the connection of the fuel pressure gage is complete.

2. Install a fuel gauge.
3. Turn ON the ignition, with the engine OFF.

Does the fuel gauge read within the specified value?

358-405 kPa (52-58 psi)

Go to Step 6

Go to Fuel System Diagnosis

6 |

1. Turn OFF the ignition.
2. Remove the Fuel Pump Relay. Refer to Fuel Pump Relay Replacement .
3. Remove the Ignition Coil/Ignition Control Module (ICM) Assembly.

Important:: Not grounding the ICM Assembly, may cause erratic spark.

4. Install a jumper wire from the ICM Assembly to ground.
5. Install the J 36012-A spark plug jumper wire kit.
6. Install a J 26792 spark tester on #1 spark plug jumper wire.
7. Ground #4 (companion to #1) spark plug jumper wire.
8. Crank the engine with the remaining spark plug jumper wires connected.
9. Repeat the above steps by installing the spark tester on #4 and grounding #1. Do the same for #2 and #3 spark plugs. Making sure the companion wire is grounded.

Does the spark tester spark on all cylinders?

--

Go to Step 7

Go to Step 15

7 |

1. Turn OFF the ignition.
2. Inspect for malfunctioning spark plugs. Refer to Spark Plug Visual Diagnosis in Engine Electrical.
3. If a problem is found, repair as necessary.

Did you find and correct the condition?

--

Go to Step 32

Go to Step 8

8 | Inspect for basic engine problems. Refer to Base Engine Misfire Diagnosis in Engine Mechanical. Did you find and correct any conditions? | -- | Go to Step 32 | Go to Step 27
9 |

1. Turn OFF the ignition.
2. Disconnect the ICM connector.
3. Turn ON the ignition, with the engine OFF.
4. Connect a DMM between the ICM ground circuit and the ICM ignition feed circuit at the connector.

Does the DMM read the specified value?

B+

Go to Step 10

Go to Step 23

10 | Connect the DMM between battery ground and the CKP sensor ground circuit at the connector. Does the DMM read voltage? | -- | Go to Step 25 | Go to Step 11
11 | With the DMM measure the resistance between the battery ground and the CKP sensor ground circuit at the connector. Does the DMM read infinity? | -- | Go to Step 12 | Go to Step 26
12 | With the DMM measure the resistance between the CKP sensor ground circuit and the CKP sensor signal circuit at the connector. Does the DMM read within the specified value. | 500 - 900 ohms | Go to Step 13 | Go to Step 18
13 |

1. With the DMM still connected and set to AC.
2. Crank the engine and observe the DMM.

Does the DMM read more then the specified value?

200 mV

Go to Step 14

Go to Step 28

14 |

1. Connect a test lamp to B+.
2. Touch the test lamp to the 7x Reference Signal circuit, then touch the Reference Low circuit.
3. Observe the CKP Activity Counter on the scan tool.

Does the CKP Activity Counter increment?

--

Go to Step 19

Go to Step 22

15 |

1. Turn OFF the ignition.
2. Remove the spark plug jumper wires.
3. Remove the ignition coil housing. Refer to Ignition Coil Replacement .
4. Disconnect the ignition coil connector from the ICM.
5. Turn ON the ignition, with the engine OFF.
6. With a DMM measure the Coil Ignition Positive Voltage circuit.

Does the DMM read B+?

--

Go to Step 16

Go to Step 19

16 |

1. Connect a test lamp between B+ and the affected coil circuit at the ICM.
2. Crank the engine.

Does the test lamp blink?

--

Go to Step 24

Go to Step 17

17 |

1. Turn OFF the ignition.
2. Disconnect the ICM connector.

Important:: DO NOT use a test lamp in the next test.

3. Connect a DMM between B+ and the affected IC Output circuit at the ICM connector.

Does the DMM read the specified value?

B+

Go to Step 21

Go to Step 20

18 |

1. Inspect/Test the CKP sensor circuit for the following conditions.

• | Poor connection

• | Open

2. If a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 32

Go to Step 28

19 |

1. Inspect the ICM connector for poor connections. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
2. if a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 32

Go to Step 29

20 |

1. Inspect the IC Output circuit for an open or poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
2. If a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 32

Go to Step 31

21 |

1. Test/Inspect the IC Input circuit for an open or poor connection at the ICM. Refer to Wiring Repairs and Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
2. If a problem is found, repair as necessary.

Did you find and correct the condition?

--

Go to Step 32

Go to Step 29

22 |

1. Test/Inspect the 7x Reference Signal for the following conditions:

• | Poor connection

• | Open

• | Short to ground

• | Short to voltage

2. If a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems

Did you find and correct the condition?

--

Go to Step 32

Go to Step 31

23 | Repair open in the ICM ground circuit and/or ignition feed circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 32 | --
24 | Repair open or short to ground in the Jumper Harness between the ICM and the Coils. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 32 | Go to Step 30
25 | Repair the short to voltage in the CKP sensor circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 32 | --
26 | Repair the short to ground in the CKP sensor circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 32 | --
27 |

1. Refer to Diagnostic Aids for the following:

• | PCM grounds

• | Stuck TP sensor

• | Skewed ECT sensor

• | Skewed or unresponsive MAP sensor

• | Loose CKP sensor

2. If a problem is found, repair as necessary.

Did you find and correct the condition?

--

Go to Step 32

--

28 | Important:: The Crankshaft Position Variation procedure must be performed. Refer to Crankshaft Position System Variation Learn . Replace the CKP sensor. Refer to Crankshaft Position Sensor Replacement . Did you complete the replacement? | -- | Go to Step 32 | --
29 | Replace the ICM. Refer to Ignition Control Module Replacement . Did you complete the replacement? | -- | Go to Step 32 | --
30 | Replace both Ignition Coils. Refer to Ignition Coil Replacement . Did you complete the replacement? | -- | Go to Step 32 | --
31 | Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | Go to Step 32 | --
32 | Attempt to start the engine. Does the engine start and continue to run? | -- | Go to Powertrain On Board Diagnostic (OBD) System Check | Go to Step 2