Troubleshooting DTC P1212

[MOWOG]

So on my way home early this week the CEL came on and the truck just died. After coasting to the side of the road it fired right back up. I drove home replaced the CPS with a new Motorcraft spare, cleaned the bowl and put in a new filter, changed the oil, and ordered an AutoEnginuity scanner from Riffraff. The codes set were P0603 and P1212 (ICP pressure lower than desired) which I think is the most relevant one. Here are the results of my troubleshooting so far (trying to duplicate the Riffraff ICP/IPR troubleshooting example).
------------------------ICP-----ICP--------ICP
-----------------RPM--Volts---Pressure---DC%
KOEO.............0.0--4.73-----0.0-------14.84
@Idle............650--4.73-----724-------14.45
Above Idle....1580--4.73-----738-------12.50
This BTW is from my signature truck. Truck was not fully warmed up, just idled a little prior to test. These numbers don't mean much to me. The ICP volts look very suspicious... they are nothing like example AE screen shots on the Riffraff website. So any light you guys could shed on these numbers would be greatly appreciated. I'm really puzzled about the ICP voltage... is this the PCM taking over after it sensed an error condition? Next steps? Jim

 

[greenskeeper]

Did you clear the codes before taking the measurements? Looks like the ECU is still in default mode.

 

[MOWOG]

First off, thanks for the reply... I haven't gotten many. But no, I didn't clear the codes before the test. So I'll do that and try rerunning the test. I've been thinking that the PCM is in some kind of 'limp mode', but I didn't know how to tell for sure. It's not like the OD light is blinking like it does for an E40D problem. Jim

 

[greenskeeper]

Clear the codes then take readings, otherwise with a CEL or SES light the ECU will give faulty readings being in fail safe mode

 

[MOWOG]

I cleared the codes and tried to restart the truck but the batteries are now low and it won't start so I'm recharging them. The AE scanner tells me that the DTC 1212 has been set again and the KOEO ICP volts are still 4.73. I'm thinking I won't be able to get a good ICP volts reading while I have this problem. The things I've been reading seem to point to a bad IPR.
Dieselmann's Tips:
No/hard start hot or after stalling, usually re-starts after cool-down; Jerky, irratic idle; Possible DTC#'s P1211, P1212, P1283:
Usually caused by low injection oil pressure or regulator (IPR) valve.
Oregon Fuel Injection:
DTC P1212; will set if 725 psi ICP is not detected in 6-15 seconds of cranking.
1. Check oil level.
2. Possible bad IPR or IPR o-rings.
So I think I'll replace the IPR and go through the fuel bowl while I'm at it. Thanks for your thoughts on the problem Greenskeeper. Jim

 

[OLDBULL8]

http://www.ford-trucks.com/forums/501097-i-found-7-3-psd-ipr-o-rings-separately.html

http://www.dieselorings.com/instruction-sheets-and-information.html

 

[MOWOG]

Well now I have a new IPR, a very nicely rebuilt fuel bowl and regulator, plus new fuel hoses and clamps, but I still have the DTC P1212 and a new one... DTC 1280 (Injector Control Pressure Sensor Circuit Low). On a little closer inspection, now I'm thinking that the ICP volts is very close to the VREF volts I'm measuring with my multi-meter. I guess this could be caused by a direct short in the ICP wiring or maybe a bad ICP. Also maybe the PCM is just setting the ICP voltage because it's in 'fail safe' mode. I don't know how I can easily check out the wiring? I will probably just replace the ICP sensor, but I'm getting a little tired of just throwing parts at it. I guess I could take it to a 'real diesel mechanic', NOooooo! Jim

 

[79jasper]

ICP sensor is something that should just be replaced. Does it have oil in the connector?

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[MOWOG]

No. No oil in the sensor. Jim

 

[79jasper]

Have you tried ohm-ing out the harness?

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[MOWOG]

I've measured resistance on the ICP sensor plug wire to ground and it looks good. The VREF wire has about 5 volts with the key on, so that looks good. There's a plug that looks like it goes to the PCM... I'm not sure about that, or the pin layout. But it looks like there's been some activity down there so maybe something's gotten buggered up? Jim

 

[79jasper]

Can you get a picture?
I can get you a pin layout for the pcm.

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[MOWOG]

You must be registered for see images attach

 

[MOWOG]

Can you see the attached pic?

 

[MOWOG]

Ok, here's a pic of what I think is the PCM plug.