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Test Description

The number(s) below refer to step(s) on the diagnostic table.

  1. (2) It is important to check for the presence of spark to all of the cylinders to isolate the problem to either EI system ignition coil inputs or outputs.
  2. (5) In checking the ECM outputs for the electronic spark timing signal, it is recommended to use an oscilloscope to view the varying voltage signals. In measuring these outputs with a voltmeter, intermittent errors may occur that cannot be seen by a voltmeter.
  3. (8) After confirming ECM inputs for the electronic spark timing to the EI system ignition coil are OK, it can be determined that a faulty EI system ignition coil is at fault.
  4. (11) After confirming proper CKP inputs to the ECM and no wiring problems present, it can be determined that the ECM is at fault.
  5. (24) This step, along with Step 25, checks for battery voltage and a ground to the EI system ignition coil.
  6. (25) If the wiring between the EI system ignition coil and the battery positive is OK, the problem is in the ignition relay circuit.
CAUTION: Use only electrically insulated pliers when handling ignition wires with the engine running to prevent an electrical shock.
DIAGNOSTIC PROCEDURE

Step Action Value(s) Yes No
1
  1. Remove the spark plugs.
  2. Inspect for wet spark plugs, cracks, wear, improper gap, burned electrodes, or heavy deposits.
  3. Replace the spark plugs as needed.

Is the repair complete?		 - System OK Go to Step 2
2 Check for the presence of spark from all of the ignition wires while cranking the engine.
Is spark present from all of the ignition wires?		 - System OK Go to Step 3
3
  1. Measure the resistance of the ignition wires.
  2. Replace any ignition wire(s) with a resistance above the value specified.
  3. Check for the presence of spark from all of the ignition wires.

Is spark present from all of the ignition wires?		 30,000 ohm System OK Go to Step 4
4 Is spark present from at least one of the ignition wires, but not all of the ignition wires? - Go to Step 5 Go to Step 12
5
  1. Turn the ignition OFF.
  2. Disconnect the Electronic Ignition (EI) system ignition coil connector.
  3. While cranking the engine, measure the voltage at the EI system ignition coil connector terminal 1.

Does the voltage fluctuate within the values specified?		 0.2-2.0 V Go to Step 8 Go to Step 6
6 Check for an open in the wire from EI system ignition coil connector terminal 3 to the Engine Control Module (ECM) connector terminal M33/ M1.
Is the problem found?		 - Go to Step 7 Go to Step 11
7
  1. Repair the wiring as needed.
  2. Connect the EI system ignition coil connector.
  3. Check for the presence of spark from all of the ignition wires.

Is spark present from all of the ignition wires?		 - System OK -
8 While cranking the engine, measure the voltage at the EI system ignition coil connector terminal 1.
Does the voltage fluctuate within the values specified?		 0.2-2.0 V Go to Step 10 Go to Step 9
9 Check for an open in the wire from EI system ignition coil connector terminal 1 to the ECM connector terminal M51/M35.
Is the problem found?		 - Go to Step 7 Go to Step 11
10
  1. Replace the EI system ignition coil.
  2. Connect the EI system ignition coil connector.
  3. Check for the presence of spark from all of the ignition wires.

Is spark present from all of the ignition wires?		 - System OK -
11
  1. Replace the ECM.
  2. Connect the EI system ignition coil connector.
  3. Check for the presence of spark from all of the ignition wires.

Is spark present from all of the ignition wires?		 - System OK -
12
  1. Turn the ignition OFF.
  2. Disconnect the crankshaft position (CKP) sensor connector.
  3. Measure the resistance between the CKP sensor terminals 1 and 2.

Is the resistance within the value specified?
  1. Measure the resistance between following terminals.
    • Terminals 1 and 3 of CKP sensor.
    • Terminals 2 and 3 of CKP sensor.

Is the resistance within the value specified?		 400-600 Go to Step 14 Go to Step 13
13 Replace the crankshaft position sensor.
Is the repair complete?		 - System OK -
14
  1. Turn the ignition ON.
  2. Measure the voltage between the CKP sensor connector terminals 1 and 3.

Is the voltage within the value specified?		 1.3-1.5 V Go to Step 20 Go to Step 15
15 Measure the voltage between the CKP sensor connector terminal 1 and ground.
Is the voltage within the value specified?		 1.3-1.5 V Go to Step 18 Go to Step 16
16 Check the wire between the CKP sensor connector terminal 1 and the ECM connector terminal M21 for an open or short.
Is the problem found?		 - Go to Step 17 Go to Step 10
17 Repair the wire between the CKP sensor connector terminal 1 and the ECM connector terminal M21.
Is the repair complete?		 - System OK -
18 Check the wire between the CKP sensor connector terminal 3 and ground for an open or short. Is the problem found? - Go to Step 19 Go to Step 11
19 Repair the wire between the CKP sensor connector terminal 3 and ground.
Is the repair complete?		 - System OK -
20
  1. Turn the ignition ON.
  2. Measure the voltage between the CKP sensor connector terminals 2 and 3.

Is the voltage within the value specified?		 1.3-1.5 V Go to Step 24 Go to Step 21
21 Measure the voltage between the CKP sensor connector terminal 2 and ground.
Is the voltage within the value specified?		 1.3-1.5 V Go to Step 18 Go to Step 22
22 Check the wire between the CKP sensor connector terminal 2 and the ECM connector terminal M5 for an open or short.
Is the problem found?		 - Go to Step 23 Go to Step 11
23 Repair the wire between the CKP sensor connector terminal 2 and the ECM connector terminal M5.
Is the repair complete?		 - System OK -
24
  1. Turn the ignition OFF.
  2. Connect a test light between the EI system ignition coil connector terminal 2 and ground.
  3. Turn the ignition ON.

Is the test light on?		 - Go to Step 27 Go to Step 25
25 Check for an open in the wiring between the EI system ignition coil connector, terminal 2 and the battery positive.
Is the problem found?		 - Go to Step 26 -
26 Repair the open in the wiring between the EI system ignition coil connector terminal 2 and the battery positive.
Is the repair complete?		 - System OK -
27 Check for a damage in the terminal of the EI system ignition coil connector and repair as needed.
Is the repair complete?		 - System OK -
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