X hits on this document

138 views

0 shares

0 downloads

0 comments

24 / 41

Three Cylinder Engines 1996-2006 Engines Using CDM Modules

NO SPARK ON ANY CYLINDER:

  • 1.

    Disconnect the black/yellow stop wires from the harness and retest. If the engine’s ignition now sparks, the stop circuit has a fault- check the key switch, harness and shift switch.

  • 2.

    Disconnect one CDM module at a time and see if the other modules start sparking. If they do, the module you just unplugged is bad.

  • 3.

    If the bottom two CDM modules are not sparking, swap the connection between the top and middle cylinder. If the middle cylinder starts sparking, replace the top CDM.

  • 4.

    Disconnect the yellow wires from the stator to the rectifier and retest. If the engine now has spark, replace the rectifier.

  • 5.

    Check the cranking RPM. A cranking speed less than 250-RPM will not allow the system to spark properly.

  • 6.

    Check the stator resistance and DVA output as given below:

CDM Pin #

A

C

700-1300 Ohms

CDM Pin #

D

A

DIODE*

CDM Pin #

A

D

DIODE*

CDM Pin #

D

B

DIODE*

CDM Pin #

B

D

DIODE*

CDM Pin #

A

B

DIODE*

CDM Pin #

B

A

DIODE*

High Tension Lead

A

700-1300 Ohms

  • *

    Diode readings are to be read one way, then reverse the leads and read again. You should get a low reading in one

direction and a higher reading in the other. NO SPARK OR INTERMITTENT SPARK ON ONE OR MORE CYLINDERS:

WIRE

Read To OEM RESISTANCE

CDI RESISTANCE

DVA

White/Green

Green/White

500-700

500-600

180V or more

Reading

Black Meter Lead

7.

Check the resistance

of the CDM as follows: Red Meter Lead

1.

2.

If the cylinders are only misfiring above an idle, connect an inductive Tachometer to all cylinders and try to isolate the problem cylinders. Using a set of piercing probes, check the trigger DVA output as shown below:

Wire Color

Check to Wire Color

Resistance

DVA Reading

Purple wire

Engine GND

Open

1V or more

White wire

Engine GND

Open

1V or more

Brown wire

Engine GND

Open

1V or more

NOTE: These triggers have the bias circuitry internally built-in, therefore you cannot measure the resistance like you can measure on the older engines.

  • 3.

    If # 1 CDM module is not sparking, disconnect the #2 CDM module and see if the #1 CDM module starts sparking. If it does, the module you just unplugged is bad. If it does not, reconnect #2, then disconnect the #3 CDM module and see if the #1 module starts sparking. If it does, the module you just unplugged is bad.

  • 4.

    If there is no spark ire on either # 2 or #3, swap locations with #1 and see if the problem moves. If it does, the module is bad. A continued no spark on the same cylinder indicates a bad trigger.

HIGH SPEED MISS:

  • 1.

    Connect an inductive Tachometer to all cylinders and try to isolate the problem. A high variance in RPM on one cylinder indicates a problem usually in the trigger or CDM module.

  • 2.

    Perform a high-speed shutdown and read the spark plugs. Check for water. A crack in the block can cause a miss at high speed when the water pressure gets high, but a normal shutdown will mask the problem.

  • 3.

    Remove the flywheel and check the triggering and charge coil flywheel magnets for cracks or broken magnets.

  • 4.

    Use the diagram below to help in locating the area where the problem may be. Remember a short in #1 can cause either #2 and #3 not to have spark. By the same reason, a problem in either #2 or #3 can cause #1 not to have spark.

57

Mercury/Force CDM Troubleshooting

Document info
Document views138
Page views138
Page last viewedMon Jan 16 13:58:21 UTC 2017
Pages41
Paragraphs4126
Words20178

Comments