1989 Ford Thunderbird SC

DIS Troubleshooting - No Start Pinpoint Tests

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N1 - PERFORM EEC-IV QUICK TEST

If there are any codes, trouble shoot those first.  If no Codes, continue.

 

N2 - CHECK FOR SPARK DURING CRANKING

Use a Spark Tester to check for spark at all spark plug wires while cranking

If there was spark present on ALL spark plug wires and they were consistent (one spark per crankshaft revolution), go to N3 otherwise go to N5

 

N3 - CHECK PIP EEC AT CRANKSHAFT SENSOR

Connect a LED Test Lamp between (+) Pin 1 on the Crankshaft sensor and the battery (-) negative lead.

Crank the engine

If the LED Test :Lamp blinks continuously during the Crank go to N4.  Otherwise replace the crankshaft sensor.

 

N4 - CHECK PIP EEC AND IGND TO EEC-IV CONTINUITY

Remove the EEC-IV from the vehicle harness connector.

Remove both connectors from the DIS.

Measure resistance between pin 56 of the EEC-IV harness connector and Pin 1 of the connector to the Crankshaft Sensor.

Also measure the resistance between Pin 16 of the EEC-IV harness connector and Pin 3 of the Crankshaft Sensor (IGND PS).

If both measurements are less than 5 then go to basic troubleshooting... Lack of fuel bad spark plugs.  If not, check for problems in the connectors or a problem with damage to a wire.

 

N5 - DETERMINE MISSING SPARK COMBINATION

Was spark missing from BOTH cylinder 1 and 5 plug wires?
or
Was spark missing from BOTH cylinder 2 and 6 plug wires?
or
Was spark missing from BOTH cylinder 3 and 4 plug wires?

If so, then go to N7  Otherwise go to N6

 

N6 - CHECK PLUGS AND WIRES  

Check spark plug wires for damage. Remove and check spark plugs for damage or wear and proper gap.

If spark plug wires and plugs are O.K. go to N7 otherwise repair the plugs/wires and retest.

 

N7 - CHECK DIS MODULE VBAT

Reconnect all cables.

Connect LED test lamp between (-) Pin 7 (IGNG D) and (+) Pin 1 (VBAT D). 

Turn the Key on

If the LED Test lamp is on, go to N8  otherwise check the connectors and service or replace the harness.

 

N8 - CHECK DIS MODULE IGNITION GROUND

Key off

Measure resistance between (-) Negative Battery connection and Pin 7 on the DIS.

If the resistance is less than 5 ohms, go to N10 otherwise go to N9

 

N9 - CHECK DIS MODULE MOUNTING SCREWS

Check if the DIS module mounting screws are corroded or loose.  Pay particular attention to the bottom ones.

If the screws are clean and tight, replace the DIS module and rerun the test.  Otherwise clean and tighten the screws. Don't forget the heat sink compound.

 

N10 - CHECK ALL COIL PACK CIRCUITS

Key on

Connect LED Test Lamp between three pairs of test points.  Note if lamp is on or off each time.

Check between (+) Pin 8 on the DIS connector and the Negative Battery Cable.

Check between (+) Pin 11 on the DIS connector and the Negative Battery Cable.

Check between (+) Pin 9 on the DIS connector and the Negative battery cable.

If the LED test lamp was on for all three checks, go to N15, otherwise go to N11

 

N11 - ISOLATE DIS MODULE SHORT(S)

Key off.

Disconnect the Pins 7 thru 12 connector from the DIS.

Connect a jumper wire between Pin 7 on the DIS (IGND D) and Negative Battery cable.

Repeat the tests in Step N10.

If the LED Test lamp was now on for all three checks, Replace the DIS Module.  Otherwise remove the jumper wire and go to N12

 

N12 - CHECK COIL PACK VBAT C

Key off

Reconnect cables to DIS

Connect LED Test lamp between (+) Pin 4 on the coil pack (VBAT C) and Negative cable on the battery.

Key On.

If the LED Test lamp is on, go to N13, otherwise check the connectors and service or replace the harness.

 

N13 - CHECK IGNITION COIL CIRCUIT

Key On

Connect the LED Test lamp between three pairs of locations given below.  Note if the LED test lamp is on or off for each one.

__ Check between (+) Pin 1 of the Coil Pack connector (C2C) and Negative Battery Cable (-)

__ Check between (+) Pin 2 of the Coil Pack connector (C3C) and Negative Battery Cable (-)

__ Check between (+) Pin 3 of the Coil Pack connector (C1C) and Negative Battery Cable (-)

If the LED Test lamp was on for all three checks, then check all connectors and service or replace the harness.  Otherwise go to N14

 

N14 - ISOLATE HARNESS SHORTS

Disconnect connector from the Coil Pack

Key off

Connect a jumper between Positive Battery Cable (VBAT +) and Pin 4 on the Coil Pack connector (VBAT C).

Repeat test procedure in Test Step N13

If the LED Test Lamp was now on for all three checks, Remove the jumper wire and check connectors and service or replace the harness, otherwise Remove the jumper wire and replace the Coil Pack.  Rerun the tests.

 

N15 - CHECK PIP IN TO DIS MODULE

Connect LED Test Lamp between (+) Pin 4 of the DIS connector (PIP D) and (-) Negative Battery Cable

If the LED Test lamp blinks when the engine is cranked go to N16 otherwise go to N22.

 

N16 - CHECK SPOUT AT DIS MODULE

Connect LED Test lamp between (+) (SPOUT) and (-) Negative battery cable

If the LED Test Lamp blinks when the engine is cranked, go to N17, otherwise go to N19

 

N17 - CHECK DIS MODULE COIL DRIVERS

Connect a LED Test Lamp between each of three pairs of test points.  Note if lamp blinks continuously for each during crank.

__ Check between (+) Pin 8 of DIS (C1D) and (-) Negative Battery Cable.

__ Check between (+) Pin 11 of DIS (C2D) and (-) Negative Battery Cable.

__ Check between (+) Pin 9 of DIS (C3D) and (-) Negative Battery Cable.

If the LED Test lamp blinks during all three checks, Replace the Coil Pack and rerun tests.  Otherwise Go to N18.

 

N18 - ISOLATE COIL PACK FROM SYSTEM

Disconnect Connector from Coil Pack.

Key off

Connected the LED Test lamp between each of three pairs of test points given.  Note if the lamp is on for each one with Key On.

__ Check between (+) Pin 8 of DIS (C1D) and (-) Negative Battery Cable.

__ Check between (+) Pin 11 of DIS (C2D) and (-) Negative Battery Cable.

__ Check between (+) Pin 9 of DIS (C3D) and (-) Negative Battery Cable.

If any LED Test lamp was on, Check the connectors and service or replace the harness.  If not, Replace the DIS module and rerun the tests.

 

N19 - ISOLATE EEC-IV PROCESSOR FOR SPOUT FAULT

Key off

Disconnect EEC-IV processor

Connect the LED Test lamp between (+) Pin 5 on the DIS Connector  (SPOUT) and (-) Negative Battery cable.

If the LED Test Lamp blinks continuously while the engine is cranked, the EEC Processor is shorting the SPOUT, replace it.  Otherwise go to N20

 

N20 - CHECK SPOUT CIRCUIT FOR SHORT TO VBAT

Disconnect connector from DIS Module Pins 1-6.

Key off

Connect LED Test Lamp between (+) Pin 5 on the DIS connector (SPOUT) and the (-) Negative battery cable.

Key on

If the LED Test lamp is on, the SPOUT is shorted to the battery. Check connectors and service or replace the harness.  Otherwise go to N21

 

N21 - CHECK SPOUT CIRCUIT FOR SHORT TO GROUND

Connect LED Test Lamp between (-) Pin 5 on the DIS connector (SPOUT) to the Positive battery cable connector.

Key on

If the LED Test lamp is on, the SPOUT is shorted to ground, check the connectors and service or replace the harness.  If the LED Test lamp is not on, replace the DIS module and rerun the test.

 

N22 - ISOLATE DIS MODULE PIP

Key off

Disconnect DIS Connector to Pins 1-6.

Connect LED Test Lamp between (+) Pin 4 on the DIS Connector (PIP D) and (-) Negative battery cable connection.

If the LED Test Lamp blinks continuously when the engine is cranked, replace the DIS module.  Otherwise go to N23.

 

N23 - CHECK SENSOR VBAT

Key off

Reconnect DIS Module Connector Pins 1-6

Connect LED Test Lamp between (+) Pin 4 on the Crank Sensor Connector (VBAT PS) and (-) Pin 7 of the DIS Connector (IGND D)

Key on

If the LED Test lamp is on, go to N24, otherwise check the connectors and service or replace the harness. 

 

N24 - CHECK SENSOR IGNITION GROUND

Key off

Measure resistance between Pin 3 of the Crank Sensor Plug (IGND PS) and Pin 7 of the DIS Connector (IGND D).

If the resistance is less than 5 ohms, go to N25, otherwise check connectors and service or replace the harness.

 

N25 - CHECK PIP S AT CRANKSHAFT SENSOR

Connect LED Test Lamp between (+) Pin 2 of the Crank Connector (PIP S) and (-) Pin 7 of the DIS Connector (IGND D)

If the LED Test Lamp blinks continuously when the engine is cranked check the connectors and service or replace the harness.  If not, then go to N26.

 

N26 - CHECK PIP S FOR SHORTS TO GROUND

Key off

Disconnect Crankshaft sensor

Disconnect DIS Module Connector Pins 1-6

Connect LED Test Lamp between (-) Pin 2 of the CrankShaft Sensor (PIP S) and Positive Battery Cable connection.

Key on

If the LED Test lamp is on, PIP S is shorted to ground between the sensor and the DIS module.  Check connectors and service or replace the harness.  Otherwise go to N27

 

N27 - CHECK PIP S FOR SHORTS TO VBAT

Key off

Connect LED Test Lamp between (+) Pin 2 of the CrankShaft Sensor (PIP S) and the Negative battery cable connector.

Key on

If the LED Test Lamp is on, PIP S is shorted to the VBAT between sensor and DOS Module.  Check connectors, service or replace harness.  Otherwise go to N28.

 

N28 - CHECK PIP EEC FOR SHORTS TO GROUND

Key off

Disconnect EEC-IV processor from vehicle harness.

Connect LED Test Lamp between (-) (PIP EEC) and Positive battery cable connector.

Key on

If the LED Test Lamp is on, check the connectors, service or replace the harness.  Otherwise go to N29.

 

N29 - CHECK PIP EEC FOR SHORTS TO VBAT

Connect LED Test Lamp between (-) Pin 1 on the Crankshaft Sensor (PIP EEC) and Negative battery cable connection.

Key On.

If the LED Test lamp is on, check the connectors, service or replace the harness.  Otherwise go to N30.

 

N30 - CHECK CRANKSHAFT VANE

Check to make sure the crankshaft vane moves through sensor air gap when the engine is cranked.  If it does, replace the Crankshaft Sensor.  If not, then you have bigger problems.  Search SCCOA for "Balancer" and "broken".