Engine/Transmission (1998.5 - 2002) what does code p-pcu mean?

[CFowler]

hi, i checked for codes because my truck has been surging at start up for a few minutes upon cold start ups and the odometer showed p-pcu. any one help me out please. thanks. carl

 

[wtfd6]

I havent heard of that one. I am curious to find out.


Mark

 

[AKAMAC]

Carl, If you watch carefully you will see, a: P-ECM b: P-PCM

They show that you have no DTCs registered in system.

You may have an injector failing on cold start, you might look at an upgrade in the near future... ...

How many miles are on the rig?

Mike

 

[CFowler]

me too. it is probaly the worst thing out there ,the way my luck has been. i hope its not the injection pump though because that means warranty work and you know who tries to do that.

 

[CFowler]

AKMAC, thanks 52,000. the lift pump failed at 21,000 and was imediatly changed out. i get 10lbs @ w. o. t. and 13-14 2 idle on the pump side and 15-16lbs before the filter.

 

[Gary - K7GLD]

The "3 ignition key clicks" used to read OBDII error codes starts a diagnostic that checks both the ECM (ECU) - Engine Control Module, and the PCU - Power Control Unit. The ECM is the larger flat computer box mounted on the driver side of the Cummins engine block below the fuel filter - the PCU is the computer box over on the firewall behind the air filter housing.



The indicator this thread refers to. P-PCU and P-ECU is to let the owner/technician know WHICH module is under test at the moment.



At least that's the way I understand it...

 

[wtfd6]

the key on test only checks the pcm. not the ecm. to check the ecm you need a scanner. thats why it has the companion codes. p1693 which tells you that the ecm has a trouble code stored.

mark

 

[Gary - K7GLD]

the key on test only checks the pcm. not the ecm. to check the ecm you need a scanner. thats why it has the companion codes. p1693 which tells you that the ecm has a trouble code stored.



mark

HMMmmm - I had figured the "PCU" was the engine power control unit at the firewall, and the "ECU" was another acronym for the ECM mounted on the engine, and that the "key click" test tested them BOTH for error codes and gave the associated error code for each...



Have to do some more reading I guess...

 

[wtfd6]

your right about pcm and ecm. the pcm is on the firewall and the ecm is on the engine.

 

[Gary - K7GLD]

your right about pcm and ecm. the pcm is on the firewall and the ecm is on the engine.

Well, yeah - but now I forget where the engine is...