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P-1309 DTC

New 11/19/2004-Updated 11/20/2004

The SHO is running fairly well, but it did stall out once last week for no apparent reason (I was about 10 ft. from stopping at a red light when it died.) Yesterday the CEL came on as I pulled up to a red light. My code scanner (permanently residing in the glove box) spit out P1309, which, AFAIK, is a vehicle specific code and has different translations for different makes and models. My el-cheapo code scanner manual skips from P1308 right to P1310, probably b/c the code has different translations. AutoZone told me that it was a generic "Ignition misfire" code.

That brings me to the V8SHO.com site, which is much more detailed.

It looks like maybe that CKPS I picked up a while ago might be needed after all. Remember? Me neither... here's the link:

In a nutshell, that link tells you that I had a stalling and uneven idle problem. I changed the IAC and TPS with no luck. I checked the front row of coils, and they all appear fine (the back ones are fairly new.) Then I reset the KAM and it ran fine. I had been about to replace the CKPS, but since the problems went away, I didn't bother.

I'm about to install the new CKPS. We'll see how that goes. Any other thoughts or tips would be appreciated.

Dan Carman
Code P1309 points to the Cam Position Sensor:
Diagnostic Trouble Code (DTC) P1309 indicates Misfire Detection Monitor is not enabled.

Key off.
Breakout box installed, PCM disconnected.
Connect digital multimeter between Test Pin 85 (CMP) and Test Pins 51 or 103 (PWR GND) at the breakout box.
Bump engine in short burst with the starter without starting engine for at least 10 engine revolutions.
Does digital multimeter reading switch between low (less than 2.0 volts DC) and high (greater than 8.0 volts DC)?


Yes No
Note: A Hall effect type CMP sensor that is installed out of synchronization will produce a DTC. VERIFY the correct installation by referring to the Powertrain/Engine Group in the Service Manual. If the CMP is installed properly, REPLACE PCM. REMOVE breakout box. RECONNECT all components. RERUN Quick Test . REPLACE CMP sensor. REMOVE breakout box. RECONNECT all components. RERUN Quick Test .

Glen Murdock

Well the new CKPS is installed now. I also checked the CMPS by removing it and inspecting it (still haven't located my multi-meter) and I found something interesting. The tip of the sensor, which is magnetized, had a buildup of extremely fine metallic dust, not unlike the "sludge" commonly found on a magnetic oil pan drain plug when changing the oil. I wonder if that small amount of metal affected the CMPS readings... :-o

At any rate, I will post my results over the next few days/weeks/months (or however long it takes my problems to come back, or when I'm convinced everything is OK.) The next step, obviously, is to replace the CMPS, which is simple and cheap ($15 part and 5 minutes labor.) I'll probably install a magnetic oil pan drain plug as well, just in case there is a small piece of weld spatter that might be causing these random nuisances at the CKPS/CMPS.

Of course, the problem could very well be elsewhere entirely. Perhaps somewhere amongst the 2 or 3 miles of wire under the hood?


Stupid CEL is still lit up. Dumped the KAM 3 or 4 times to be sure, but it comes right back on when I start it up. Still spitting out P1309. I suppose now I HAVE to replace the CMPS as the next step. The CMPS wiring looks fine. The wiring going to the CKPS seemed OK, but I couldn't trace it back more than a few inches from the sensor.

And my intuition tells me this could all still be related to a bad coil. I hate those things.


Anyone think this might be related to the actual trigger on the cam? My car was Kirked about one year ago, and I'm sure if the trigger ring was loose Kirk would have aligned it and tacked it down. However, it seems that a mis-aligned trigger ring would certainly tell the PCM to spit out P1309, doesn't it?


I guess the more apt question would be how long will it take me to pull the valve cover and see if the trigger ring is loose? And, assuming that it is indeed loose, how will I know where it belongs so I can correct the problem?

Here's some background I found on that nifty website:


I'm still waiting on the final resolve. Rumor has it Dan has taken out a gun permit????




Well, I was about to pull the valve cover to inspect the CMPS trigger ring, and then it started raining. :-( Since I already had the appearance cover off, I poked around a little bit to see if there were any loose connections or anything. The little grey connector near the top of the appearance cover (just in front of the intake runners) was a bit loose, so I pushed it back together. By loose, I mean the plastic parts of the connector were snapped together tightly, but the metal female terminal inside was hanging out the end of the plastic connector, just barely touching the male part. I slid it back in and felt that it made a positive connection.

I also noticed the turquoise connector that's supposed to be attached to the front of the A/C compressor was hanging off. Thinking this might somehow impact the connection/wiring to the CKPS, I pushed it back where it belongs. I buttoned everything back up and reconnected the neg battery cable. Fired it up--no CEL! Hopefully it will stay that way!

I still don't know what the problem was, but at this point I'm happy. :-)



You're close, but these cars don't use Hall Effect sensors.

The V-6 cars had Hall Effect sensors for crank and cam. This system was called Low Data Rate EI Ignition. They called it that because the square wave coming from the sensors, all be it a true digital signal, was still not fast enough to conform to OBD-II compliance for Misfire Detection.

In the Duratec engines (including our V-8), the system is called High Data Rate EI. They still have crank and cam sensors, but are PM Generators that produce an A/C voltage. These sensors are a coil of wire wrapped around a solid iron core. As the toothed wheel on the crank or single pin on the cam, pass near the pole of the sensor a positive voltage is induced. When the tooth is adjacent to the pole, there is no voltage and as the tooth moves away from the pole, a negative voltage is induced. So the output of these sensors is an A/C voltage that the computer measures and counts in cycles. There are 35 teeth on the crank trigger wheel, but room for 36 teeth. One tooth is missing (sorta like it's from Alabama). The computer reads this A/C signal and uses the missing tooth for TDC reference.

Hope this answers a few questions, but it might generate a few more.

Doug Lewis

If I'm Dan, I'm not sure I'm doing the Happy Dance just yet!!


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