Boost control circuit? SES light

[DA BIG ONE]

I've had a turbo boost control circuit problem for a long time now with the SES light coming on and staying on.

I know the pink wire @ solenoid is hot when cranking and while running with the PCM grounding the yellow wire to control boost @ solenoid. After tinkering I find that the yellow wire never gets a ground from the PCM so I'm guessing the relay inside PCM that controls the ground has gone south. I verified the turbo boost control circuit is not grounding at any rpm or speed using a multimeter hooked to the ground and a hot wire.

Have any of you ever changed out this relay, or is it a PITA to do?

[More Power]

The wastegate solenoid is controlled via PWM (Pulse Width Modulation) by varying wastegate solenoid ON time. It's not a direct grounding, but a variable one.

The PCM grounding of the wastegate solenoid is not likely done via a relay, but rather a silicon junction that applies the ground via PWM.

Jim

[DA BIG ONE]

Jim, I'm guessing here that I should get some voltage reading at multimeter, or?

If this circuit is toast, is there a way I can shut off the SES light for that boost control circuit w/o device controller, or does it need to be turned off w/tec2 or some other device controller?

Right now the setting is at turbo boost control circuit is set @ 100% I checked this reading with my Car Code OBD2 scanner, it does have a device controller for turbo boost circuit.

Readings should be 50 to 70% @ idle and 20 to 40% @ 2,500 rpms so I'm thinking if I set it to 0% it would shut off SES light, or?

[joed]

I haven't experimented with the boost controller setting on my Carcode. I don't think you can 'set' it and have it remain there - that should be a programming setting in the PCM. You could verify by setting it to a certain value, close Carcode, then re-open it and see if the wastegate duty matches your previous setting.

I'm not sure you would want to set the duty cycle at 0% anyway - I think that would mean the wastegate can go completely open and boost performance would suffer.

Have you tried 'rebooting' the PCM by disconnecting battery power for a few minutes? Sometimes this cures some 'quirks'.

Joe.

[DA BIG ONE]

I haven't experimented with the boost controller setting on my Carcode. I don't think you can 'set' it and have it remain there - that should be a programming setting in the PCM. You could verify by setting it to a certain value, close Carcode, then re-open it and see if the wastegate duty matches your previous setting.

I'm not sure you would want to set the duty cycle at 0% anyway - I think that would mean the wastegate can go completely open and boost performance would suffer.

Have you tried 'rebooting' the PCM by disconnecting battery power for a few minutes? Sometimes this cures some 'quirks'.

Joe.

This quirk has been with me since changing out pmc to Heath stage 3 setup, tinkered with it before to no avail, now just want to get the light turned related to the boost control circuit off forever.

I have a manual boost control and truck runs fine, Carcode through device control does reset this % value this how I reset it to 100% thinking it would allow the light to turn off, thinking 0% maybe the trick but not sure. Other wise I've been told a tec2 is needed to shut down the light.

[joed]

I didn't realize you had manual boost control. You may as well try setting it to 0% - worth a shot.

[JohnC]

Th PCM adjusts the duty cycle to get a desired manifold pressure. Manually adjusting the duty cycle will have no effect on the light unless you happen to hit a dutycycle that results in the desired manifold pressure. Since you have a manual boost control, it ain't gonna happen.

Bottom line, Heath PCM + Heath boost control = heath problem.

For those readers with a functional vacuum boost control system, the way to test the solenoid wiring is with a dwell meter. Idle should read about 70%.

[DA BIG ONE]

Th PCM adjusts the duty cycle to get a desired manifold pressure. Manually adjusting the duty cycle will have no effect on the light unless you happen to hit a dutycycle that results in the desired manifold pressure. Since you have a manual boost control, it ain't gonna happen.

Bottom line, Heath PCM + Heath boost control = heath problem.

For those readers with a functional vacuum boost control system, the way to test the solenoid wiring is with a dwell meter. Idle should read about 70%.

I suspect there is no way to shut light down for the turbo boost circuit, or is there?

How about resistor to fool the boost sensor, or?

[joed]

Have you talked to Heath about the issue? What is the specific code? P0236?

I suspect the code is occurring because you're boost levels are higher than desired. It should be something that can be handled with the programming - they should be able to increase the 'desired' boost ranges, or increase the max. constant (window) above the desired to avoid the code. There may even be an option to turn off the particular code. Regardless, it will require a reflash of the PCM.

A boost fooler like Kennedy sells or the resistor trick should also work.

[JohnC]

The PCM turns the light on. Either the boost control is turned up too much (or maybe not enough) or the programming needs to be changed.

[DA BIG ONE]

Have you talked to Heath about the issue? What is the specific code? P0236?

I suspect the code is occurring because you're boost levels are higher than desired. It should be something that can be handled with the programming - they should be able to increase the 'desired' boost ranges, or increase the max. constant (window) above the desired to avoid the code. There may even be an option to turn off the particular code. Regardless, it will require a reflash of the PCM.

A boost fooler like Kennedy sells or the resistor trick should also work.

P1656 TURBO BOOST CONTROL CIRCUIT

[DA BIG ONE]

The PCM turns the light on. Either the boost control is turned up too much (or maybe not enough) or the programming needs to be changed.

I'm thinking program too......