007_e350

I just put both new batteries in (2 weeks ago) - Ran great until today, at a long stop light when I gunned it I got ABS Malfunction, ESP Malfunction and Low Battery convenience features disabled & my steering wheel went really hard ----- This used to happen before replacing the old battery

Also, last night I had to turn the car off and keep left park lamps on for abt 6 ~ 7 mins - Would they've drained the battery out ?? Why does the steering wheel go hard ? After I turned the car off & back on, everything was normal

Diesel Benz

Ten minutes with partial parking lights does not kill even a poor battery. Do you mean the battery warning remains on or was it just temporary? And have you measured the battery voltage (both batteries)?

007_e350

It was temporary - but it should never have come up being brand spankin new batteries - I put it in Dyno Mode menu where voltage is readable, it was 12.4 before starting and remained between 13.4 - 14.2 volts while driving

Diesel Benz

Even a new battery can loose charge and the convenience features switched off message can come. But I understand in your driving scenario it should not have appeared.

What was the voltage of the other battery (don't be lazy, take the multimeter ). I was just wondering if the SBC battery relay would have been bad and did not charge the small battery. I guess it could be temporary too but then you should have had the red battery warning.

Was only this one time that you saw the switch off message? Did you only change your batteries, the rear-SAM is original?

007_e350

Yeah the Rear SAM is original - I only changed batteries out

I even got this message today - I had been listening to radio for abt an hour with the car switched off -- The battery was at 12.3 -- when I cranked up it gave me ESP, ABS Malfuntion & the LOW BATTERY CONV FEATURES DISABLED ... I kept it running & it charged up to 14.2 ... Then shut it down and cranked again, no alarms ever since

Why is ABS & ESP associated w/ Low Batt ? This started happening after I bled my brakes without disconnecting SBC pump (2 months ago)

Before bleeding brakes, I did used to get LOW BATT CONV FEATURES DISABLED warning but no other messages -- do you see a link somewhere ?

Diesel Benz

If your AUX (SBC) battery is good, you should not get ABS/ESP warnings along with low battery. But SBC brakes need a well charged backup battery and if the small battery is low from charge, you would typically get a red warning.

It could be normal to reach 12.3 Volts from using the radio for an hour (you would have a lot of other consumers on in too). But I would like to see the SBC battery voltage at this time, before you start the car.

007_e350

Just measured all voltages before starting the car this morning:

- Aux Battery (with one terminal disconnected): 12.6 volts
- Main Battery (with Aux Batt terminal disconnected): 12.48 volts

Here's my concern:
Old Aux battery (Fiamm) lying in the garage also had 12.58 volts
Old Main Battery (MB) also lying in the garage also had 12.4 volts

I also noted: while unlocking the doors SBC pump clicked thrice but didn't buzz brakes lines - I remember it ALWAYS used to buzz upon unlocking ... This has been happening since brakes were bled w/o disconnecting this darn pump

Could it be the Aux battery Relay (under the vipers) being bad ?

Update:
Aux Batt stays at 12.66 even with the car running, is Alternator not charging this one ?

Diesel Benz

The alternator can only charge the AUX battery if the relay works and connects both batteries to the same voltage. You could measure the voltage over the relay when the engine is running.

But do your brakes work properly otherwise? The fact that the pump runs more than once sounds alarming.

007_e350

This morning Main Battery read 12.2 volts...
Brakes work fine - now what do I do ?

Diesel Benz

Have that fixed!

007_e350

You mean the Aux batt relay ... But somebody told me it wont charge aux batt till it needs charging ... Or should both batteries read 14v when cars running ?

Diesel Benz

No, I mean the charging issue. This voltage is too low when the engine is running. The AUX battery is always in need to get charged and is charged if the main battery voltage is higher and allows the AUX battery to get charged.

007_e350

This relay will be energized by BCM to enable charging of Aux battery - BCM checked out fine .. What should I do to get aux battery charged ?

Diesel Benz

But you cannot assume charging is OK if the BCM is OK. The alternator needs to work too.

I actually mean your battery voltage is obviously too low when the engine is running and this needs to be fixed, what ever part is causing this.

mdrcls55

Left the lights on my CLS55 on last week (valet turned them to ON, didn't notice it). Was able to jump the car and after 15 minutes of driving the message came up that said Convenience functions have been restored. But after a week of normal starting and driving the features haven't been restored. ipod and steering wheel controls still don't work.

Any ideas? Even though the low voltage warning isn't coming up anymore could the battery not be strong enough now? I thought there was a second battery under the hood for some functions.

Diesel Benz

Sounds like you've killed some control unit(s) when jump-starting the car, or at least confused one or more. How exactly did you jump start it?

mdrcls55

Jumper cables to the battery in the trunk. Let it charge for a minute, then started the car and disconnected them.

erifly

Not sure if its related but I used to get the exact warning and found out after taking a look that the battery cable was loose..had to tighten it..and it solved the problem.