Diesel Data: Automotive Repair

Component Test

ECU Component Pin-Outs:





1. Using a voltmeter, back probe ECU terminals IGT and E1.

NOTE: To prevent flooding during testing, don't crank engine for more than 1 or 2 seconds at a time.

2. Crank or start engine.

Standard Voltage: 0.7 - 1.0V

3. If no voltage reading was obtained in step #2 recheck voltage substituting body ground for terminal E1.

4. If voltage was present in step #3, inspect wiring and connection between ECU terminal E1 and body ground. If wiring and connection were not at fault replace ECU.

5. If voltage was not present in step #3, inspect fusible link, ignition switch, wiring and connectors between battery, ignition coil (+), and igniter assembly.

6. If no faults were found in steps #1 through #5 proceed with this test. If faults were found and corrected, verify problem still exists prior to proceeding with this test.

Ignition Coil, Primary Testing:





7. Using an ohmmeter, measure resistance between ignition coil (+) and (-) terminals.

Primary Resistance (Cold): 0.24 - 0.30 ohms

Secondary Coil Testing:





8. Using an ohmmeter, measure resistance between ignition coil (+) and the secondary terminals.

Secondary Resistance (Cold): 9.2k - 12.4k ohms

9. Check ignition coil for signs of carbon tracking, burned or discolored plastic, external leakage, or cracks in the housing.

10. If ignition coil resistance is not within specifications or physical damage is apparent, replace ignition coil.

Pickup Coil Testing:





11. Disconnect primary wire connector at distributor.

12. Using an ohmmeter, measure resistance between terminals G1 and G-.

G1 Pickup Coil Resistance: 125 - 190 ohms

13. Using an ohmmeter, measure resistance between terminals G2 and G-.

G2 Pickup Coil Resistance: 125 - 190 ohms

14. Using and ohmmeter, measure resistance between terminals NE and G-.

NE Pickup Coil Resistance: 155 - 240 ohms

15. If resistance was not within specifications in steps #12 through #14, replace distributor assembly. If no faults were found, proceed with this test.

Pickup Coil Air Gap:





16. Using a non magnetic feeler gauge, measure the gap between the signal rotor and its related pickup coil.

Air Gap: 0.008 in (0.2 mm) or more

17. If air gap is not within specifications, replace distributor assembly.

18. If no faults were found in this testing procedure, replace igniter unit.