Few issues- RPM surge, ABS light intermittent, stall

[S13Hitman]

2002 TB, passed down to me from good friends, 198k miles and has always been extremely dependable to the original owners. Seems to be in great overall shape outside of these gremlins/issues I'm having. I've cleaned out the TB so far with it off of the truck, reset ECM for 30 mins. Also replaced ign. switch and the exhaust camshaft solenoid that requires moving the power steering pump to the side.

First off I had no issues for almost a month until I had to drive long distances and things would be intermittent after about an hour of driving. I'd be cruising at 65mph and the RPMs would surge around the 3k mark, then the ABS light would come on without a check engine light coming on. After about a week or 2 of the hour+ long trips, the truck started stalling on me while on the highway. It allowed me to restart it at first but the following week it was worse. Not cool since I'm bringing my pregnant wife and child to a specialist, which is the reason for the long rides.

1st breakdown in the middle of nowhere. The RPMs would surge, the ABS light would come on and the truck would stall. Every mile or 2 it just kept happening and limped to a gas station. I did the few changes I mentioned above, had a check engine light for the exhaust solenoid so this was included in my things to do. Truck restarted but my tow truck driver said he had a TB with similar issues and it was a gremlin in the ignition near the key.

Had a mobile mechanic come out to trace the ignition issue and he found a bad ignition wire that was broken. He drove all around town with his reader hooked up and it seemed to be running great. 2 weeks later I'm on a 1 hr drive and the truck doesn't stall on me but the RPMs start surging again, ABS light back on and I have the whole family with me! Arggg

Who has had a similar issue and knows what the problem is? I wish I was good with a multimeter but I'm not, can't really afford to spend much more either. Please help me...

Edit- My mechanic said the wire was broken due to the harness just being very tight around where it looms through and not being long enough.

 

[mrrsm]

There are several good postings on this unusual problem here on GMT Nation but for the sake of brevity… this highlighted excerpt from the listed link explains the problem (s) that may be at the heart of the matter ...in a nutshell:

https://www.justanswer.com/chevy/4bem6-06-chevy-trailblazer-stalling-dieing-problem.html

“The problem is typically in the electronic throttle controls. This encompasses the sensor in the accelerator pedal, the computer, the wiring, and the throttle body. Once I have the codes, I can better narrow down what part of that system is causing the problem. The Traction control and stability systems are disabled by the computer when these problems occur, that is why these lights are on as well.”

(1) For later model engines with a MAF Sensor at the Air Box... Bad Connectors or Broken Wires hidden inside wrapped wire harnesses.

(2) The Throttle Body is going T*TS Up... Damaged Gears, Loose Butterfly, Bad Connector Pins.

(3) The Accelerator Pedal is going T*TS Up... Failing Sensor or Damaged Rheostat inside.

(4) If anyone Monkeyed around under the hood... trace any Cut or Broken or Frayed wiring to the MAF Sensor, (if there) The TB Cable connector... and/or the ACC Pedal Wiring and Connector inside the cab under the dash panel could be making poor contacts.

...and Last but Not Least..
(5) A Low Quality, Non-OEM Ignition Switch should be looked at with a very jaundiced eye.

Getting and logging the historical codes with an inexpensive OBDII Code Reader will be necessary to narrow down the search and not involve having to change out each component unnecessarily by playing "The Parts Changing Guessing Game".

 

[Capote]

The ignition switch causes various electrical issues when it starts to crap out. Most of which include the ABS light to come on when there is no ABS issue occurring. If I were you i'd go about replacing the ignition switch with another ACDelco one (do not buy an aftermarket one); to see if this clears up any issues.
ACDelco D1426D GM Original Equipment Ignition Switch

 

[Mooseman]

Bad grounds have also been known to cause issues like this as well. Several threads about them.

For engine rpm surging, it is also.possible that the torque converter clutch is slipping. Best way to confirm this is to get a Bluetooth OBD adapter with the Torque Android app to read TCC slippage rate. If at a steady speed it fluctuates or is not near 0, it's slipping, probably caused by a worn valve in the transmission valve body.

 

[S13Hitman]

So i did replace the switch with an ac delco already. Exact one.

Just received bluetooth scanner and got code p0013. Ive already replaced this part so is it the wiring or would a bad ground still throw this code?
CPAS i think. Camshaft position acuator sensor.
So i attempted to trace some wires and was overwhelmed quickly with that harness around the fuse panel.

To MRRSM thanks so much for all that info. Im bringing it to a shop unless theres an easier way to check through all of this.
My mobile mechanic wont respond, what a surprise.

 

[S13Hitman]

I dont see where the TCC slippage rate is on torque. Ill keep looking but is that only in the purchase version maybe?

 

[mrrsm]

I realize that you have already replaced the CPAS recently... However, of absolute necessity... this process must also include Changing your Oil Filter and Motor Oil at the very same time. This is because even with the install of a Brand New CPAS... the Contaminated Engine Oil WILL re-clog the New CPAS. This detailed video provides quite an excellent look into the problems involving the CPAS when the DTCs of P0013 or P0014. The Narrator provides additional step-by-step actions using very simple means of diagnosing BOTH codes. His hands on method will improve your understanding of some inexpensive methods of trouble chasing these DTC issues.

The Variable Valve Timing being regulated here is only a mere 25 Degrees of variable retardation of the Exhaust Camshaft... but the changing Oil Pressures that will vary the position of the Exhaust Camshaft achieves this depending upon the RPM Band it is in and thus can be greatly affected by either a loose or broken harness connector and wires which can become contaminated with Old Oil that leaks from around a squashed or flattened CPAS "O"Ring sealing it to the head.

Likewise... the presence of any Dirt and Mung clogging the oil flowing into and out of the VVT Exhaust Camshaft Phaser courtesy the re-clogged screens inside of the the CPAS will negatively affect the VVT actions. I think that you will enjoy this particularly edifying video:

 

[Mooseman]

What brand CPAS did you use? Dorman are junk. ACDelco or Delphi should be used.

P0013 has nothing to do with the sensor, only the CPAS.

And as @MRRSM said, oil maintenance is important on these.

 

[S13Hitman]

So my mechanic says he cant find any issues and thinks it has something to do with the tranny. I haven't picked it up yet to ask why he thinks that. Maybe it is the TCC...

I did change the oil with the selenoid replacement. Im not sure what brand sensor i purchased. Got it from advanced auto parts.

 

[S13Hitman]

Does anyone have a FSM? 02

 

[S13Hitman]

Okay my mechanic said the tranny was slipping on the reader. Someone said it could be that. Im surprised with that due to the mph needle jumping and turning the ABS light on.
How much am i looking for to replace the TCC

 

[Mooseman]

I know for a fact that a slipping anything in the tranny would not affect the ABS. My son had a slipping TCC and no ABS light. Our member in France also had a slipping TCC and no ABS issues.

It could be slipping, either a gear or the TCC (likely the TCC since it has a slip % check). That can be eliminated with a shift correction kit. Very common issue. If the varying RPM while cruising goes away when you tap the brake, it's the TCC.

 

[S13Hitman]

Okay so ill see if tapping the break when rpms vary. The crazy thing is it wont happen until about an hour of driving.
Whats a shift correction kit?

Will unplugging the tcc help me test any of this?

Also, i feel like its a short or a bad ground. I asked the shop to check these things but who knows what they really checked.

Today the mph would flicker. Then abs light on. Then check engine for same code. I think im going to get a good multimeter and read up on using it with an FSM. Just need to find a fsm...

 

[Mooseman]

Whats a shift correction kit?

4L60E valve body upgrade kit, AKA P1870 "code buster"
Code Buster shift kit installation (OffRoadTB.com)

Will unplugging the tcc help me test any of this?

Can't do that without unplugging the whole transmission.

Just need to find a fsm...

If you mean a manual, then just look at my signature with a link to them.

 

[S13Hitman]

OKay I have some news about the history from a local garage. This should help.
The same exact issues happened to the original owner. The MPH and RPM needles would flicker and dance around and then the ABS and check engine light would come one. The breaks shake when applied after this happens. Then the truck would stall, which it has been doing it again.

The original owner had this TB in the shop for 2 weeks with them trying to figure it out. It wound up being a bad pin going into the PCM. Since they didn't sell this part anymore they had to work it out. The paperwork I received from the shop doesn't say which pin or circuit but I'm hoping someone here would know. It has to be a circuit that ties into the ABS, possibly the gauge cluster as well. Everything basically goes haywire at once.

I agree with the shift kit upgrade! But it sure seems like there is another issue going on. It must be the wiring into the PCM after what I found out, maybe someone has had the same problem.

 

[mrrsm]

Post #4...

https://gmtnation.com/forums/threads/bcm-pinout.16994/#post-533371


... also... it might be worth checking the Vacuum Line at the two connection points at the Power Steering Vacuum Boost Unit and the Intake Manifold. A Bad Vacuum Leak there could stall the engine when the Brakes are suddenly applied.

 

[Mooseman]

That's the BCM, he needs PCM.

However, a PCM issue would not affect the ABS or the gauges like you describe. I still think it's a wiring or ground issue somewhere. Even though you replaced it, it could also be a defective ignition switch, especially if it's not an ACDelco.

 

[mrrsm]

The 5 Pinout images shown in Post #4 of the link above do show all of the wire diagrammed connectors to the GM 4.2L PCM ...as well as some other engine sensor connectors.

 

[Mooseman]

The 5 Pinout images shown in Post #4 of the link above do show all of the wire diagrammed connectors to the GM 4.2L PCM ...as well as some other engine sensor connectors.

My bad. Read the title and not the post itself.

Still think it's a wiring issue.

 

[mrrsm]

This link supports your suspicions about it being a Wiring Problem and offers a way to run down the problem on a wide array of GM Trucks and SUVs suffering with the ABS Intermittent Dash Light issue:

http://www.gm-trucks.com/forums/topic/75722-abs-light/

 

[S13Hitman]

Update. The shop is saying the fuse box under the hood is toast. I just dropped off a junkyard pulled one in hopes it'll work.

They are back ordered with gm right now which makes sense if these are common to replace. What do yall think?

He said it wasn't getting power. Im worried he has no clue but he is a 35 yr master mechanic... Praying. The trans is slipping but could a bad relay in the box cause issues with the TCC?

 

[S13Hitman]

I didn't mean relay but if the fuse box is crap then certain relay's wont work. So could possibly be a bad connection causing the TCC relay to act up?

 

[Mooseman]

I've heard of the underhood box melting down but this is a first for interior one. Since these trucks have been out of production since 2009, not surprised that such a part is possibly no longer available. A used one should be fine anyway.

 

[S13Hitman]

So the shop said power is coming out of fuse box now but there's a wiring issue coming out into firewall.
F.ing wonderful.

When i was at the junkyard. I noticed the TB next to the one i sourced from had not just the fuse box taken out of it, but the entire wire harness going into the interior and the gauge cluster. I wish i had the time to go back and just do the same damn thing

 

[Mooseman]

OK, stupid question. He/you checked the mega-fuse on the underhood fuse box?