How to check Crank angle sensor wire for continuity?

[Clay]

Background

• Replaced the old unit with an oem crank angle sensor
• CEL (P0335) still illuminated
• All timing marks line up
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• Timing retarded from 5 to 3 at WOT, 2nd gear, running lean!
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• Old crank angle sensor shows no sign of physical contact with the back plate, no crankwalk
• Car does not start when the crank angle sensor is disconnected

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I suspect the crank angle sensor wire, ecu harness side, may have gone bad. How do I check the wire leading back to the ecu for continuity? I have a cheap digital multimeter btw. I also consulted with RRE and Glendale Mitsubishi about the problem, which leads me to believe the wire maybe damaged/separated under the insulator. While this problem could also be a hundred other things, does anyone have insight in to my problem?

Searched and found a similar problem, thread.

 

[luv2rallye]

I suspect the crank angle sensor wire, ecu harness side, may have gone bad. How do I check the wire leading back to the ecu for continuity?

First test if there is +12V (to ground) on the CPS connector red wire with key on. Then key off and disconnect battery negative. Unplug ECU. Connect one lead of the meter (set on lowest ohms scale) to pin 89 of the ECU connector (http://www.vfaq.com/mods/ecu-harness-2G.html). Stick a safety pin through the insulation of the blue w/white stripe wire on the sensor side (so it will test the connector also) of the CPS connector (or in from the connector back if you can reach the wire). Connect the other meter lead to the safety pin. You should have continuity (0 ohms). If not, test to the other side of the connector (to eliminate connector). If everything ok now test the black wire for continuity to ECU pin 13.

 

[Clay]

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Voltage checks out at 12.11 (Red, ground wire) and 4.98 (Blue wire).

Instead of sticking a pin into the blue wire, I alligator clipped the connector (sensor side) blue wire prong. Then connected a lead into pin 89. The result was 1 ., is that infinity?

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When I switched, black multimeter lead, into the ECU wire side the results changed to 00.7.

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Is this the correct way of doing the continuity test?

 

[luv2rallye]

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Voltage checks out at 12.11 (Red, ground wire) and 4.98 (Blue wire).

Good

Instead of sticking a pin into the blue wire, I alligator clipped the connector (sensor side) blue wire prong. Then connected a lead into pin 89. The result was 1 ., is that infinity?

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Yes that is infinity but you have it unplugged so of course there is no connection (infinity) to the ECU. Perhaps I wasn't clear that you must leave the plug connected. So you want to connect the test lead to the wire before the plug on the sensor side (why I said use a safety pin through the wire insulation) so that you are testing the connection in the connector (in case it's bad) as well as to the ECU. Redo this.

But first - with connector unpluged press on the pins with your finger to make sure they're locked in place and they also look ok (not corroded, full of dirt, loose, make good contact, etc). And pull/push connector out/in a few times to see if it "feels" right (sometimes pins don't seat or are loose so when connector is pushed together they just push the pin back. Of course if your meter is connected you can just watch it there too - should get less than 0.7 ohms again).

When I switched, black multimeter lead, into the ECU wire side the results changed to 00.7.

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Good, this means wire from CPS connector (ECU half) to ECU is ok.

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Is this the correct way of doing the continuity test?

Yes except you need to redo what I said above. Yep that looks like pin 13. Also I forgot to tell you to wiggle all these wires while testing to find if they are partially broken. And you need to stick the test lead into the wires on the sensor side with the plug connected for all the tests (mechanics use a probe with a sharp tip on it for either this way or into the back of the connector sensor side (plug still connected) along the wire till it touches the metal pin inside the connector). I suggest a redo - sorry.

 

[Clay]

Thanks for the correction. Going to try the test again.

 

[luv2rallye]

You asked how to test continuity so that's what I gave.
But if you want to test the sensor you need to measure the connected plug blue/white wire while cranking or idling: http://www.dsmtuners.com/forums/showthread.php?p=151265626#post151265626
So is the problem fixed and car running ok now? Still getting P0335?

 

[Clay]

The results are 00.5 for both pin 89 (Blue/white wire) and pin 13 (Black wire).

Crank position sensor test, clarifying the steps, because i'm confused.
* Stick a safety pin into the blue/white wire (Sensor side)
* Connect a multimeter lead to the safety pin

* Which wire should i connect the other multimeter lead? Red or Black (Sensor side)?

I connected one lead into the blue/white wire and the other into the red wire, with cps connected, voltage remained at 12.XX at idle. Voltage was at 11-12 during cranking.

 

[luv2rallye]

The results are 00.5 for both pin 89 (Blue/white wire) and pin 13 (Black wire).

Crank position sensor test, clarifying the steps, because i'm confused.
* Stick a safety pin into the blue/white wire (Sensor side)
* Connect a multimeter lead to the safety pin

* Which wire should i connect the other multimeter lead? Red or Black (Sensor side)?

I connected one lead into the blue/white wire and the other into the red wire, with cps connected, voltage remained at 12.XX at idle. Voltage was at 11-12 during cranking.

ok with meter set to read voltage and leads in correct meter jacks for voltage, connect the positive lead to the safety pin (blue/white) and the negative lead to either ground or the black wire. The signal is pulses but they should read an average on the meter (anything between 0.4 - 4.0V).

The way you had it connected (to red wire which is battery voltage through MPI relay) doesn't prove anything because the battery voltage itself is probably the 11-12V while cranking and 12.xx at idle.

 

[Clay]

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During cranking, the volts went from 0.17 - 2.0. At idle, the voltage checks out at 2.04.

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Just showing how I re-routed the crank angle sensor wire out of the timing cover. I drilled a few holes into the cover.

I don't know what the hell is going on anymore. Thanks for the help luv2rallye, going to bring the car to Satan.

 

[luv2rallye]

What makes you think the CPS is bad? Just because you still have P0335? It sounds to me like it's working. Did you reset the CEL by disconnecting battery negative for 5 minutes?

 

[Clay]

Yes, i have disconnected the negative battery terminal for five minutes and over night. Also used pocketlogger to clear the CEL only to have it come back with the next key on. The car continues to pull/retard timing severely while driving, which is why I suspect the CPS. The main radiator fan is always on too, not sure if the fan is related to the CPS problem.

11/13/07 UPDATE: Replaced the ECU and everything is back to normal. Bought an Eprom Ecu from http://www.enginecontrolunits.com/index.html