ESP/BAS SERV 4WD

[Davood]

2010 1500 4WD lifted 4" Rough Country. ESP/BAS SERV 4WD flashing light alternating: Reset lights (U0415, and C1464) but they came back. Found a munched wire loom at the front differential, all 4 wires to the 4WD actuator were mashed and shorted together. repaired (solder splice and 2 layers of shrink-wrap). cleared codes, and again they returned after driving about 5 miles. Measured voltage at front wheel speed sensors 12 V present, measured about 500Kohms to both front sensors, removed both rear wheel speed sensors, measured 12 v present at both rear connectors. However, reading resistance both wheel speed sensors read over limit (greater than 20Mohms) seems odd.

any help appreciated. and by the way happy fathers day to all the dads out there.

 

[Tach_tech]

C1464 is for the front axle disconnect. So there’s no point checking wheel speed sensors if you don’t have any codes for them.

Do you have power to the front axle disconnect on the pink/green wire. Should also have continuity to ground on the black wire.

 

[Davood]

Thanks, I will check but I did head the solenoid pulling in, and the 4WD lights were illuminating properly, so I did not think to look.

 

[Davood]

yes, check both the intermediate connector and at the actuator, and both have 12 V present when the Ignition is ON

 

[Tach_tech]

What about the ground? Does it have continuity to battery ground?

 

[Davood]

Yes 12V present at both the intermediate connector, and directly at the actuator. Still wondering, when measuring the impedance of the rear wheel speed sensors what should be the expected value. It's really odd to read open circuit on both sensors, however the 4WD is new to me and they both could be bad

 

[Davood]

yes continuity to ground, hence +12V nd return are present at actuator, the display also indicates that the unit is switching thru all modes properly

 

[Tach_tech]

Ok, so when you measured the 12V it was across the pins at the axle disconnect connector.

Are you still getting the code set? Are you able to clear it. if the codes still there you’d have to check the signal and return wiring from the disconnect to the drivetrain control module.

 

[Davood]

yes codes still present, cleared them but have not taken it out for a test drive yet. The truck (FRANK) is up on blocks, had all 4 wheel speed monitors disconnected at one point so I had error codes all over the place. cleared them all. Had the wonderful (or stupid?) idea to put the car in D and witness the wheels spin while up in the air. Wheels will not spin and the brake pedal gets engaged, I guess that is the whole Traction Control thing... Did not try to engage 4WD while FRANK was lifted. The U0415 was active. the C1464 was stored, does it take a number of power cycles to disappear even if it was erased?

 

[Tach_tech]

The U0415 is just an informational code. Means the ABS module has received some implausible data.

I would maybe do a capacitive discharge. Disconnect both battery cables, then touch the positive cable to the negative cable. This will discharge any remaining voltage in the system. Leave the battery disconnected for 30 minutes. Then test operation and see if you have any codes or warning lights coming back.

 

[Davood]

Nice. Will do that this morning before I drop the truck and drive it.

 

[Davood]

So up to this I also inspected, disconnected, and reconnected all the connectors, and cleared the codes. Today, did the capacitor discharge thing, and left the leads off the battery for a few hours. Then let the truck down and took a test drive different direction, but same results after about 5 miles (less than 10) the ESP/ BAS and SERV 4WD alternately flashing. (forgot to mention the TCS light (off to the side of the display) also lights up when this happens. This time I had a friend's code reader attached. verified all 4 wheels are sensing the same speed, after the lights lit up and in a dirt parking lot went thru the 4WD and 4WD Low, the only odd thing was coming out of 4WD low. got home, read the codes and there were new ones: both Left and Right Front Door codes (stored) whatever, but the interesting new code is the brake pedal sensor C1000 Brake pedal position sw# 1 circuit performance. So down under the brake pedal, if you look closely @ the switch: it will only be activated (change of state), if I were to lift on the pedal. looks like an 1/8th inch shim (honestly maybe even a 1/16th inch shim)would do the trick. could there be air in the ABS body? The brakes seem fine to me, but I did need to replace both front brake hoses as the front end was trashed: new axles, lower control arms, shocks, brakes, rotors, and hoses. Is there a special bleed process for the ABS??

 

[Tach_tech]

There is a bleed procedure for the ABS module. A faulty brake switch can cause those lights to happen as well. So I’m assuming the other code C1464 didn’t come back?

 

[Davood]

ok so I fixed it for penny (temporary fix). masking taped a penny to the metal plate on the brake pedal. I will look for the brake pedal adjustment tomorrow. So the penny got rid of the ESP /BAS light, but without clearing the code, if I would idle for an extended period of time, the ABS and BRAKE light would go on and stay on until I put it in drive and got above 5MPH. repeated twice, but once I cleared the C1000 code, that went away too. I will look or the brake pedal height adjustment screw tomorrow. and will let you know if the problem returns.