Hello all,
I have a 2002 911 Carrera manual, that seems to start run and drive normally, but continues to throw code P1371. The engine is all stock except for a K&N intake. It (the DTC) used to be just on occasion, then the frequency steadily increased. Now it continues to return every time the car is driven. From what I can find the code is for valve lift control checksum error, above limit. When this code is thrown, it is almost always stored with cylinder 1/2/3 valve lift and/or misfire codes. Does anyone have experience with the particular code?
Thanks in advance for your help!
Will

 

Probably 1 or more lifters not switching over to large lift, You say almost always bank 1, does it sometimes do it for bank2 as well? You wouldnt be able to pin point exactly which tappet was malfunctioning so replacing all the intake lifters on that bank would be the only way to go. You would be able to tell if you had 1 bank or both banks with malfunctions by watching fuel trims on a datalogger while the car is accelerated to wot , I suggest taking it in, either way its not something I would reccommend as a do it yourself. And as for why it didnt appear all the time, you arent going into valve lift change until high in the rpm band, 5000+rpms

 

Thank you for the response, sorry it has taken me so long to reply.
Yes the codes are always specific to bank 1, but the cylinders ofter vary?
If it is indeed the lifters, I have a few questions.
1. Why does it only happen to one bank?
2. Why is it not specific to just one cylinder on that bank?
Thanks!

 

This may have something to do with the variocam actuator on bank#1. The variocam actuator is controlled and monitored by the ECM and would explain the checksum error and stored DTC for Bank#1. All valve timing, lift, and duration are controlled by this one mechanism for all three cylinders in the bank. The occasional misfire code may be related to when the ECM requests a valve timing change and does not get it. In time, it could be any of the three cylinders that misfires. The ECm would then retard engine and possibly valve timing to avoid engine damage.

A hydraulic lifter problem would probably result in only a misfire code as the engine computer has no sensor input into the actual amount of valve lift or duration accomplished by the cam lobes and valve lifters. It would only have information provided by the variocam as to its operation of its electro-hydraulic functions.

The concentric hydraulic lifters used on the intake valves are operated by the variocam locking 'fast' cam lobes and 'slow' lobes together to increase duration and lift. The lifters, however, are just along for the ride.


Please update this thread when you get it repaired. I am shopping for a 996 and have decide on a later model 996 because of variocam+ technology amoung other reasons. Would be curious to know the outcome.

 

The lifters are what control the high/low lift to happen. It is a 2-stage lifter that has a pin locked into place to allow the high lobes on the cam to acuate the lifter further, allowing the valve to be pushed open further. There is a spring inside the lifter that allows the high lift lobes to be absorbed when not actuated. There are 3 intake lobes per valve, 1 central lobe for low lift, and 2 high lift lobes, 1 on each side of the low lift. Sort of an (IiI) formation.

 

hallo, I 'm Pietro and I'm writing fron Italy. I have a 07 Cayman 2.7

Since a few days I have a similar issue with my car.
I Have the following errors (always all together), without CEL ( I read it with Durametric), they appear after I do a few kilometers

P1371 - Valve lift control checksum
P1362 - Valve lift control cylinder 4
P1364 - Valve lift control cylinder 5
P1360 - Valve lift control cylinder 6

My setup is Setup: Cayman 2.7l 11/2006, 5 speed MT, IPD PLENUM, V-Flow Airfilter, Superspirnt CATLESS Headers, Milltek Catback CATLESS, Lightweight AASCO Flywhell, Cargraphic Underdrive Pulley.


Could someone help me?

Happy new Year!

 

did any of you have this valve lifter check sum error taken care of (i know its been a while since the last post) I have this same issue/error. It's at the dealer now. They first thought it was a coil problem, now they think its worse since it keeps on misfiring