Hi,

Few time ago came “service vehicle soon” light. For now every time when I start car and ABS and traction control light will on. Its blinking about 20min.
and today came extra “reduced power” and if I looked fault codes and there was many:
P0135
P0141
P0155
P0161
P1571H
P1630
P1689H
B0432
U1040H
B2284H
B2285H
C2120H
Can anyone advise what to check?

Thanks

 

First off, Are ANY of the DTCs in a CURRENT STATE?
Second, CLEAR ALL of the DTCs. Turn the Ignition OFFF. NEXT- Restart the engine. WITHOUT turning the ignition / engine off, Use the RESET button to clear any of the DIC Messages. Press/Hold reset until they clear.
Next, READ the DTCs WITHOUT turning the ignition OFF.
List ALL of the new DTCs and make sure to list if they are CURRENT "C" or HISTORY "H"

Give us that NEW info.

NOTE! Its important to read the DTCs in the same ignition cycle WITHOUT turning the ignition off. Some DTCs clear them selves or turn to history once the ignition is turned off and then back on.

Bill

 

I make like you said and falults what coming back are:
U1040 H C
B0431 H C
P1630 H

I mentioned if I turn ignition off for few seconds and then on( not starts) and then came “reduced power” and one extra fault was P1221.

Is this normal that menu 28-TCS are- NO COMM. when engine is run?

 

P-1630 is the Theft Deterrent Learn Mode Active. The Resistive Pellet in your key is not being read when you install the key into the ignition switch OR the value of that signal is not getting to the BCM. Try your spare key / clean the key contacts for the pellet You stated that the key cam be pulled out when the ignition is ON. That means you need a NEW lock cylinder. The lock cylinder assy also contains the little module that reads the Key Resistive pellet.

P-1221 Fuel Pump Relay control circuit OPEN or SHORTED. Remove the Fuel Pump Relay. Carefully examine the Pins on the relay and the female pins in the fuse box. Look for corrosion, darkening of the pins, spread female pins in the fuse box. Get an old fuse. Break it in half. Use the half of the fuse to insert into the female pins in the fuse box. When you insert or extract the fuse half in the fuse box female pins, you should feel a nice tight grip on the fuse blade.

In MY honest opinion, You have to fix the 1630 as it is preventing you from cranking/starting the engine. Purchase a NEW Lock Cylinder/VATs Module. If you remove the ignition switch, you can take the ignition switch and the new lock cylinder to GM Dealer OR a Locksmith and have it rekeyed to match you OEM Key. To be SURE if the VATS module is reading the key chip, you can disconnect the VATS pigtail and read the two wires with an OHM Meter. It should match the resistance of the little Resister chip in your key. Then you have to make sure that it getting to the BCM.

 

Looking at your initial DTC's on your first post looks like an ignition switch issue...all 4 O2 heater circuits, U1040 "no comm" with TCS...B2284 and B2285...left and right door modules...C2120...TPMS malfunction...each of these modules or circuits are fed from one of the 4 main feed wires out of the ignition switch which would be the ORANGE wire if you look at those power feeds... @Bill Curlee can possibly verify my hypothesis.

 

ABSOFRIGGENLUTELY CORRECT! I didn't want to just spit that out without clearing the DTCs and seeing what reappeared. The ignition switch can have good days and bad days. Just because you didn't get that same DTCs as your initial writing, next time you may get more. The LDCM / RDCM are usually the first to complain about a low voltage issue and or no comms. Usually caused by low or weak battery.
As C5 DIAG stated, the ignition powered modules are pretty predictable indicators of a faulty ignition switch contact/s.

It looks like your switch is most likely working on that last ignition cycle. Maybe it will have issues on the next or day after.