vsc slp brake lights on, engine missing, idpm replaced, no difference.

[LABMAN1]

Hi, new to the forum, longtime titan and qx56 owner. Have a 2004 qx56 with idpm symptoms, but the idpm was replaced last week and this did not correct the issues. Issues are as follows: flashing cluster lights, vdc, slip, brake, cruise, rpm gauge. This follows with the engine misfiring off and on. The only other change or replacement was a new battery prior. The qx would not start one morning, so jumped it and drove to NAPA and replaced. Tested voltage while issues were active and showed 14.5 volts while running. After battery replacement, started having issues, researched and seemed like a classic idpm relay or board failure, purchased a new improved board, but no change. Took to Infiniti today, and of course vehicle issues were not present when dropped off. They called later to say the instrument cluster was bad and not allowing communication with other controls and would have to be replaced before any further diagnosis would continue.... Also showed bank one cat failure. I am unsure as to how to move forward from here. Any advise would be greatly appreciated.
Gong to bed soon, work is early, will check forum soon. Thanks again.

[LABMAN1]

ANY IDEAS!!! NEED HELP PLEASE

[marctronixx]

the instrument cluster on the qx is the brain of the canbus system. all the sensors and any faults will pass through it.

if the cluster is damaged internally, this can throw all sorts of codes because the sensors are not able to communicate reliably.

if you have access to a obd/scan tool, pull any codes at the obd port.

i agree with the dealer unfortunately, the instrument cluster needs to be replaced before anything else can be done.

search for a salvage one with the same trim/options that's verified working.

[LABMAN1]

Codes were recorded when engine was missing, C1185, C1156,C1132,U1001, and P1212. ANY HELP WOULD BE GREAT. THANKS AGAIN.

[smola]

check brake fluid level

[LABMAN1]

Brake level just a little low, maybe a 1/4 inch???? Threw more codes today and brakes grinded and when turning wheels sounded like they were grinding, shut off and restarted, everything fine, pulled these codes this time:5

ABS C1156, C1185,C1000, TRANS U1000, P1705, ECM P1212 TCS COMM LINE 1 U1000

[LABMAN1]

PLEASE. NO ONE HAS ANY IDEAS OR SIMILAR PROBLEMS???? WOULD APPRECIATE SOME HELP.

[smola]

Is it under minimum level? If it is change brake pads before adding it.

[marctronixx]

OP,

as i stated, the instrument cluster SHOULD BE REPLACED!!! the dealer is correct they have done this before because the clusters of that vintage will go bad. that is probably causing more than half of your issues!