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C0021-02 Brake Booster - General Signal Failure


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As I was working on my vehicle (Previously had crankshaft/camshaft issues) all of a sudden, I got the following codes:

 

-C0021-02 code which is Brake Booster - General Signal Failure

-C121C-00 Torque Request Signal Denied

-C212A-16 System Voltage - CIrcuit Voltage Below Threshold 

-U0401-00 Implausible Data Received from ECM/PCM "A"

-C2101-17 Battery Voltage High - Circuit Voltage Above Threshold.

 

(The battery was overcharged, it's tested at 14V, and now we are trying to run it down.)

 

The car is driving and braking smoothly when the ground is level, I can drive forward and reverse with no (braking) issues. But when I drive up the driveway (10%-20% incline, then levels outs) the BRAKE light comes on the dash and then the pedal gets rock hard and it becomes difficult to brake. This happens when I am going forward or reverse into the driveway. 

 

How should I approach these? 

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Battery is fine, can't overcharge a lead acid battery unless alternator is faulty. You had a high and low codes, could be surge from something else. Your meter may not be perfectly accurate. Start by checking master cylinder brake fluid level in reservoir under hood.

 

If a incline is causing the light to come on it could be low, should be between max and min marks. The light being triggered could cause random codes from abs. As brake pads wear the fluid level goes down; caliper pistons moving out to auto adjust.

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1 hour ago, John/Horace said:

Battery is fine, can't overcharge a lead acid battery unless alternator is faulty. You had a high and low codes, could be surge from something else. Your meter may not be perfectly accurate. Start by checking master cylinder brake fluid level in reservoir under hood.

 

If a incline is causing the light to come on it could be low, should be between max and min marks. The light being triggered could cause random codes from abs. As brake pads wear the fluid level goes down; caliper pistons moving out to auto adjust.

Hey John,

Thank you for responding. Yes, the brake fluid reservoir was a little under the middle so I filled it up but the issue is still there. I did order new brake pads and rotors and will be installing them this weekend.

 

If the issue continues, what would you look at after? 

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42 minutes ago, DodgeBruhBoy said:

Hey John,

Thank you for responding. Yes, the brake fluid reservoir was a little under the middle so I filled it up but the issue is still there. I did order new brake pads and rotors and will be installing them this weekend.

 

If the issue continues, what would you look at after? 

not just an issue of pads and rotors, but that caliper slide pins are "free" and not seized. And also that rear calipers are also in good "order".

 

BTW.....WHAT was the cause/fix to the crank/no start/timing chain issue????? many folks gave their time and suggestions to try and assist you, it would be nice to find out what was going on. 

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