It this Limp Mode for an '01 ?

[Sierra]

Son driving to work evening shift last Monday on the freeway ... Car cut's power - He takes the turn off ..... NO BRAKES !! Had to use us emergency Lever.


Car still stutters/limps along - But still no brakes on the foot petal at all.

Tow it home and check the new H-5 Battery (or is it H-8 ?) Check the Oil for water - all clear - Check Fuse #32 - Good ..........

Anyone have the root cause idea by chance ?



xEnox - whatever just rebuilt after shipping to Canada and receiving it back for the ECM 7 months and 3K miles ago for near $800
Got a new MAF for around under $175'ish - And other filters.
Timing Pump,Water Pump,Thermostat - Coolant just 2000+ miles ago.

Idles on 3 cylinders it sounds like - 2 k rpm's idle and above - smooth -- Under load- No Go and still as well as ever - No Brakes.

Can it be the Turbo or possibly even the vacuum pumps ? Looking for east test - with answers that are clear.

This is the only thing that is showing up on the window ...

https://preview.ibb.co/iz9psR/IMG_1954.jpg (https://ibb.co/dinLz6)

[AKAMick]

The brakes are not drive by wire, check brake fluid level, they should remain operable despite electrical failures, though without power assist.

[hoonk]

.. Car cut's power - He takes the turn off ..... NO BRAKES !!


Car still stutters/limps along - But still no brakes on the foot petal at all.


Idles on 3 cylinders it sounds like - 2 k rpm's idle and above - smooth -- Under load- No Go and still as well as ever - No Brakes.



How about a large air leak - from the "ejector" (or can be called a vacuum pump, and yes your 2001 does not have the electric vacuum pump a 2003 does)

They are plastic and break apart, makes car idle too fast, sputter (lean) and with no vacuum for the brake booster the car is very hard to stop. When the car idles too fast the ecu tries to shut off injectors to keep the idle speed normal -

(i trust when you say "no brakes" the pedal is hard and NOT going to the floor)

Look for a 30665561

[Sierra]

Thanks so much Hoonk - I'll defiantly order this part and report back !

[Sierra]

Thanks so much Hoonk !


Found the Root Cause right away on your reply !! - And this was the first time I got the chance to look into it while working a shutdown on 14 hour night shifts. Thankfully they give us Sundays off for one day a week.


https://preview.ibb.co/drPhXR/IMG_1992_790.jpg (https://ibb.co/kBDbsR)


https://preview.ibb.co/i7zue6/IMG_1993_791.jpg (https://ibb.co/kRsEe6)

[nickbw]

First comment I have on seeing your picks is WTF has been done to the wiring loom? My O1 still looks brand new under the hood and car has a hard life, driven hard and odd road too.