Vacuum Pump
 

:su: Last week my abs & brake light came on so this weekend I pulled a brake job on the truck. New pads & shoes two new wheel cylinders & one new drum, all new brake fluid and bled system. Brakes work gr8, still have lights. So last night on the way to work I'm noticing that with the cruise that tc seems not to be staying locked & the warning lights are going out at higher rpm. I don't have a vacuum gauge (obtainable), but I wouldn't know what to look for. Any & all help accepted.

have you had the codes read on why the lights are on? i'm not sure if your truck can be looked at by a MOTIS (snap-on) or whatever one Matco makes or if it has to be done by the dealer..... find out those code numbers and i can help you more. there may be others on here that can tell ya what's going on right now without codes. they will post up in a bit.

codes
 

I haven't had the codes read. argve1 tried to pull them up with ignition but no luck, I'll look into getting the codes read. It will be a few days I'm working 12's this week.

Doesnt work on a 99 at all....and only marginally works on other years - you need a scanneer to see any codes that may be set.

Any oil on the ground under the Vacuum pump? They will usually leak a bit of oil

Autozone or most other parts shops will read the codes for free and give you the results. Just be sure to let us know what comes up.

No tell tales under truck at all. Will be getting them read in the morning after work. Will post the results.

---AutoMerged DoublePost---

Stopped this morning and my favorite mechanic read my codes, didn't even lift my skirt. Well here they are; 35-rear sensor open, 37-intermittent signal?,51-rear isolation solinoid open, 54-dump valve?, 82 number of tone ring teeth out of range. So do I pull both speed sensors and the one on top of the diff? Maybe a wire harness is bad? Maybe crawl around under the truck repeating every healing prayer I've ever heard:puke:? The codes with "?" flashed to fast to actually read and would come and go.

For future reference - Dude since you are storing my tools you have a vacuum gauge - it's either in my Dad's tool box or it's still over in my garage sitting and waiting on the next load to go over. Ok i'll be over on friday evening and we'll dig into it - we can use my welder :tttt:

here's for the 35 code:

http://i150.photobucket.com/albums/s...our/99abs2.gif

http://i150.photobucket.com/albums/s...mour/99abs.gif


Symptom
Rear Sensor Open

When Monitored:
Ignition On.The CAB continuously monitors the wheel speed sensor circuits. The CAB sends a small signal through the sensor circuits. If the CAB does not receive the proper signal back, a Sensor Open DTC is set.

Set Condition:

1. No output signal from any sensor for initial 1.0 second period.
2. Continuously excessive sensor resistance for subsequent 1.0 second period.

Possible Causes

* CAB CONNECTOR OBSERVABLE DEFECT
* REAR WSS (+) CIRCUIT OPEN
* REAR WSS (+) CIRCUIT SHORTED TO GROUND
* REAR WSS (-) CIRCUIT OPEN
* REAR WSS 2-WAY CONNECTOR OBSERVABLE DEFECT
* REAR WSS DEFECTIVE
* REAR WSS OBSERVABLE DEFECT
* WSS WIRING HARNESS OBSERVABLE DEFECT

here's for the 37 code:

http://i150.photobucket.com/albums/s...our/99abs3.gif

http://i150.photobucket.com/albums/s...our/99abs4.gif

Symptom
Intermittent Signal From Rear Sensor

When Monitored:

1. No output signal from sensor for 15 ms.
2. Average filtered wheel speed computation above 12 mph with the brake released or above 20 mph with the brake pedal applied. OR

1. Rear wheel acceleration reversing sense in between two sampling periods.

Set Condition:

2. Magnitude of rear wheel acceleration or deceleration exceeding 3 g in the second sample period.
3. Criteria 1 and 2 satisfied 128 times within a 21 second period.

Possible Causes

* CAB CONNECTOR OBSERVABLE DEFECT
* REAR WSS (+) CIRCUIT OPEN
* REAR WSS (-) CIRCUIT OPEN
* REAR WSS 2-WAY CONNECTOR OBSERVABLE DEFECT
* REAR WSS DEFECTIVE
* REAR WSS WIRING HARNESS OBSERVABLE DEFECT
* REAR WSS/TONE WHEEL OBSERVABLE DEFECT
* WSS WIRING HARNESS OBSERVABLE DEFECT

here's for the 51 code:

http://i150.photobucket.com/albums/s...our/99abs5.gif

Symptom
Rear Isolation Solenoid Open - EBC-2

When Monitored:

1. ABS power relay closed.
2. Valve command for a particular solenoid not present (not trying to turn the valve on).

Set Condition:

3. Low feedback voltage from the low side of solenoid.
4. Criteria 1-3 satisfied for over 40 consecutive controller checks spaced 5 milliseconds apart.

Possible Causes

* HCU 4-WAY CONNECTOR OBSERVABLE DEFECT
* HCU 4-WAY CONNECTOR/HARNESS OBSERVABLE DEFECT
* HCU ASSEMBLY DEFECT
* REAR ISOLATION VALVE CONTROL CIRCUIT SHORT TO GROUND