• If you currently own, previously owned or want to own an Avalanche, we welcome you to become a member today. Membership is FREE, register now!

Engine Code Help Please!!

MTBJoe

SM 2003
Full Member
Joined
May 7, 2002
Messages
599
Location
So Cal
I've been having some wierd things going on with my 2002 Z71 Av over the past few months. Nothing major just some warning lights coming on and going off for no reason and a couple times I experienced a huge lost of power off the line (not racing just normal driving). Since I'm out of warrantee I decided to get one of those scanguage devices which is awesome and if finally paid off (I think).
This morning it acted up so I ran a scan and came up with the following error codes and looked up what they were on the internet.

B1000 - ECU Malfunction
P1860 - PWM Solinoid Circuit Electrical
P0758 - Shift Solinoid Circuit Electrical
P0785 - 2-4 brake timing control Solinoid

Can someone please shine some light on what these could possibly mean before I take my poor Av in?

Thanks!
 
Hmmmmmm....

I hate to sound like broken record.....but Ignition switch?

It seems when it goes out..all sorts of things happen..and codes as well..

most of the codes deal with the tranny...and then sometimes the gage cluster does not work properly....

check some of the other posts about IGNITON switch...and read up...may be they have some similar symptoms....

good luck
 
There's a collection all right! Different areas eng, trans & brakes.

May all be can be related. (Like the over-oiled air filter/MAF sensor faults.) But that would need more looking into to confirm that.

Is there moisture in the PCM area? Connectors? Wire rubbing & worn insulation?

I'll see what comes up...
 
2002

DTC B1000 - kw inoperative OnStar #PI02038 - (Apr 29, 2004)

When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.
Condition/Concern:

DTC B1000
Circuit Description

The internal fault detection is handled inside the control module. No external circuits are involved.
Conditions for Running the DTC

The module runs the program to detect an internal fault when power up is commanded. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.
Conditions for Setting the DTC

The module has detected an internal malfunction.
Action Taken When the DTC Sets

The module refuses all additional inputs.
Conditions for Clearing the DTC

* A current DTC clears when the malfunction is no longer present.
* A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Diagnostic Aids

* This DTC may be stored as a history DTC without affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the module.
* If this DTC is retrieved as both a current and history DTC, replace the module.


DTC B1000 stored as a current code in the OnStar VS-3B system.

CAUSE: Internal VIU/VCIM failure
Recommendation/Instructions:

Replace VIU/VCIM with appropriate part number. The replacement part must be ordered through General Motors Technical Assistance - OnStar. After installation of new part, the technician must either call OnStar enrollment at 1-888-667-8271 prompt #1 and update the customers OnStar account with the new Station ID (StID) found on the part or do an OnStar button press. The technician will be required to offer their dealer code to the OnStar Advisor in order to gain access to update the account. After updating the account, the OnStar center will need to reconfigure the OnStar system.

.

Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.
Models:

(1998 - 2001 Cadillac Catera) and (1998 - 2004 Cadillac DeVille) and (1998 - 2002 Cadillac ELDORADO) and (1999 - 2004 Cadillac Escalade 4WD) and (1998 - 2004 Cadillac Seville) and (2002 - 2004 Chevrolet Avalanche 2WD and 4WD) and (1999 - 2004 Chevrolet Blazer 2WD and 4WD) and (1999 - 2004 Chevrolet Blazer/Trailblazer 2WD and 4WD) and (2000 - 2004 Chevrolet Impala) and (1999 - 2000 Chevrolet Lumina) and (1999 - 2004 Chevrolet Monte CARLO) and (2000 - 2004 Chevrolet Suburban 2WD and 4WD) and (2000 - 2004 Chevrolet Tahoe 2WD and 4WD) and (2000 - 2004 Chevrolet Venture) and (2000 - 2004 GMC Denali) and (1999 - 2004 GMC Envoy 4WD) and (1999 - 2003 GMC Jimmy 2WD and 4WD) and (2000 - 2004 GMC Yukon/XL 2WD and 4WD) and (2001 - 2004 Pontiac Aztek) and (2000 - 2004 Pontiac Bonneville) and (2000 - 2004 Pontiac Grand Prix) and (2000 - 2004 Pontiac Montana) and (2000 Pontiac Transport) and (1999 - 2004 Buick Century) and (2000 - 2004 Buick LeSabre) and (2000 - 2004 Buick Park Avenue) and (1999 - 2004 Buick Regal) and (2001 - 2003 Oldsmobile Aurora) and (1999 - 2004 Oldsmobile Bravada ) and (1998 - 2003 Oldsmobile Intrigue) and (2000 - 2004 Oldsmobile Silhouette)
 
DTC P1860

756906-TqConv_Clutch.gif


Circuit Description

The torque converter clutch pulse width modulation (TCC PWM) solenoid valve controls the fluid acting on the converter clutch valve. The converter clutch valve controls the TCC application and release. The solenoid attaches to the control valve body within the transmission. The solenoid receives ignition voltage through the OFF/ON/CRANK voltage circuit. The powertrain control module (PCM) controls the solenoid by providing a ground path on the TCC PWM solenoid valve control circuit. Current flows through the solenoid coil according to the duty cycle, percentage of ON and OFF time. The TCC PWM solenoid valve provides a smooth engagement of the TCC by operating during a duty cycle percent of ON time.

When the PCM detects a continuous open, short to ground or short to power in the TCC PWM solenoid valve circuit, then DTC P1860 sets. DTC P1860 is a type B DTC.
Conditions for Running the DTC

? ?* The system voltage is 10-18 volts.
? ?* The engine speed is greater than 450 RPM for 5 seconds.
? ?* The engine is not in fuel cutoff.
? ?* The PCM commands first gear.
? ?* The TCC duty cycle is less than 10 percent or greater than 90 percent.

Conditions for Setting the DTC

DTC P1860 sets if one of the following conditions occurs for 5 seconds:
Condition 1

The PCM commands the solenoid ON, 90 percent, and the voltage feedback remains high, B+.
Condition 2

The PCM commands the solenoid OFF, 0 percent, and the voltage feedback remains low, 0 volt.
Action Taken When the DTC Sets

? ?* The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
? ?* The PCM inhibits TCC engagement.
? ?* The PCM inhibits 4th gear if the transmission is in hot mode.
? ?* The PCM freezes shift adapts from being updated.
? ?* The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records.
? ?* The PCM stores DTC P1860 in PCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

Conditions for Clearing the MIL/DTC

? ?* The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.
? ?* A scan tool can clear the MIL/DTC.
? ?* The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
? ?* The PCM cancels the DTC default actions when the fault no longer exists and/or the ignition switch is OFF long enough in order to power down the PCM.

Test Description
 

Attachments

  • 756906-TqConv_Clutch.gif
    756906-TqConv_Clutch.gif
    73.1 KB · Views: 64
DTC P0758

756900_2-3_Shift_Sol_4L60x.gif


Circuit Description

The 2-3 shift solenoid (SS) valve controls the fluid flow acting on the 2-3 shift valves. The solenoid is a normally-open exhaust valve. With the 1-2 SS valve, the 2-3 SS valve allows four different shifting combinations. The solenoid attaches to the control valve body within the transmission. The 2-3 SS valve receives ignition voltage through the OFF/ON/CRANK voltage circuit. The powertrain control module (PCM) controls the solenoid by providing the ground path on the 2-3 SS valve control circuit.

When the PCM detects a continuous open, short to ground or short to power in the 2-3 SS valve circuit, then DTC P0758 sets. DTC P0758 is a type A DTC.
Conditions for Running the DTC

? ?* The system voltage is 10-18 volts.
? ?* The engine speed is greater than 450 RPM for 5 seconds.
? ?* The engine is not in fuel cutoff.

Conditions for Setting the DTC

DTC P0758 sets if one of the following conditions occurs for 5 seconds:
Condition 1

The PCM commands the solenoid ON and the voltage feedback remains high, B+.
Condition 2

The PCM commands the solenoid OFF and the voltage feedback remains low, 0 volts.
Action Taken When the DTC Sets

? ?* The PCM illuminates the malfunction indicator lamp (MIL).
? ?* The PCM commands third gear only.
? ?* The PCM commands maximum line pressure.
? ?* The PCM inhibits TCC engagement.
? ?* The PCM freezes shift adapts from being updated.
? ?* The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records.
? ?* The PCM stores DTC P0758 in PCM history.

Conditions for Clearing the MIL/DTC

? ?* The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.
? ?* A scan tool can clear the MIL/DTC.
? ?* The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
? ?* The PCM cancels the DTC default actions when the fault no longer exists and/or the ignition switch is OFF long enough in order to power down the PCM.



 

Attachments

  • 756900_2-3_Shift_Sol_4L60x.gif
    756900_2-3_Shift_Sol_4L60x.gif
    69.1 KB · Views: 64
DTC P0785

756904_3-2_Shift_Sol_4L60x.gif


Circuit Description

The 3-2 shift solenoid (SS) valve assembly is a normally-closed, 3-port, on/off device that controls the 3-2 downshift. The solenoid attaches to the control valve body within the transmission. The solenoid receives ignition voltage through the OFF/ON/CRANK voltage circuit. The powertrain control module (PCM) controls the solenoid by providing a ground path on the 3-2 shift solenoid valve control circuit. During a 3-2 downshift, the 2-4 band applies as the 3-4 clutch releases. The PCM varies the timing between the 3-4 clutch release and the 2-4 band apply, depending on the vehicle speed and the throttle position.

When the PCM detects a continuous open, short to ground or short to power in the 3-2 SS valve assembly circuit, then DTC P0785 sets. DTC P0785 is a type B DTC.
Conditions for Running the DTC

? ?* The system voltage is 10-18 volts.
? ?* The engine speed is greater than 450 RPM for 5 seconds.
? ?* The engine is not in fuel cutoff.

Conditions for Setting the DTC

DTC P0785 sets if one of the following conditions occurs for 5 seconds:
Condition 1

The PCM commands the solenoid ON and the voltage feedback remains high, B+.
Condition 2

The PCM commands the solenoid OFF and the voltage feedback remains low, 0 volts.
Action Taken When the DTC Sets

? ?* The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
? ?* The PCM commands a soft landing to third gear.
? ?* The PCM commands maximum line pressure.
? ?* The PCM inhibits TCC engagement.
? ?* The PCM inhibits 4th gear if the transmission is in hot mode.
? ?* The PCM freezes shift adapts from being updated.
? ?* The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records.
? ?* The PCM stores DTC P0785 in PCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

Conditions for Clearing the MIL/DTC

? ?* The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.
? ?* A scan tool can clear the MIL/DTC.
? ?* The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
? ?* The PCM cancels the DTC default actions when the fault no longer exists and/or the ignition switch is OFF long enough in order to power down the PCM.
 

Attachments

  • 756904_3-2_Shift_Sol_4L60x.gif
    756904_3-2_Shift_Sol_4L60x.gif
    70.6 KB · Views: 65
The images expand large size, so you can view them better.

HTH!
 
Wow, thanks for all the info!

I forgot about the ignition switch so I'll read up on that.

Was thinking about it all day yesterday and came up with one (rather obvious) theory.

As far as I can tell these weird things only happen in the morning and they started a few months ago (about the same time winter did). I park my Av outside and although it hasn't rained much it gets pretty wet in the morning so maybe there's moisture causing the problems?

I think I'll try resetting the codes and see if/when they come back.
 
As was mentioned, ign switches have a bit of a history causing problems, as does over-oiled K&N (or similar) air filters. (Yes, those air filters cause transmission problems when they(A/C's) are not cleaned & serviced correctly!)

The Av should be able to handle cold weather, what temp's are those mornings?

Is the problem sporadic or a set pattern that you can expect the fault to occur?

 
Here's one:

Malfunction Indicator Lamp (MIL) On, Transmission Stuck in Second or Third Gear, Instrumend Cluster Inoperative (Replace Ignition Switch) #01-07-30-002D - (Oct 19, 2004)

2004-2005 Buick Rainier

1999-2000 Cadillac Escalade

2002-2005 Cadillac Escalade, Escalade EXT

2003-2005 Cadillac ESV

1997-1999 Chevrolet Full-Size Pickup, Suburban, Tahoe (Old Style)

1997-2005 Chevrolet Blazer, Corvette, Express, S-10

1999-2005 Chevrolet Silverado (New Style)

1999-2005 Chevrolet Blazer RH Drive (Export)

2000-2005 Chevrolet Suburban, Tahoe

2002-2005 Chevrolet Avalanche, TrailBlazer, TrailBlazer EXT

2004-2005 Chevrolet Colorado

1997-1999 GMC Sierra, Suburban, Yukon (Old Style)

1997-2001 GMC Jimmy

1997-2005 GMC Savana, Sonoma

1999-2005 GMC Sierra (New Style)

2000-2005 GMC Yukon, Yukon XL

2002-2005 GMC Envoy, Envoy XL

2004-2005 GMC Canyon, Envoy XUV

1997-2004 Oldsmobile Bravada

2004-2005 Pontiac GTO

2003-2005 HUMMER H2

with 4L60-E, 4L65-E, 4L80-E or 4L85-E Automatic Transmission (RPOs M30, M32, M33, MT1, MN:cool:

This bulletin is being revised to update model years, add additional models and 4L80/85 Transmission Information. Please discard Corporate Bulletin Number 01-07-30-002C (Section 07 -- Transmission/Transaxle).

Condition

Some customers may comment on one or more of the following conditions:

* The Malfunction Indicator Lamp (MIL) is ON.
* The transmission is defaulted to second gear (4L80/85-E).
* The transmission is defaulted to third gear (4L60/65-E).
* The instrument cluster is inoperative.

Upon investigation, one or all of the diagnostic trouble codes (DTCs) P0740, P0753, P0758, P0785, P0787, P0973, P0976, P1860, P2761, P2764 and P2769 may be set depending on the vehicle.

Cause

The most likely cause of this condition may be a loss of voltage to the transmission on circuit 1020. This loss of power may be caused by an open in the ignition switch. This condition may also be the result of an incorrect installation of an aftermarket electronic device such as a remote starter or alarm system.
 
sperry said:
The most likely cause of this condition may be a loss of voltage to the transmission on circuit 1020. This loss of power may be caused by an open in the ignition switch. This condition may also be the result of an incorrect installation of an aftermarket electronic device such as a remote starter or alarm system.

Is there a circuit that DOESN'T go through the damned ignition switch? ;)
 
This is just FYI, as it isn't the codes you had mentioned.

Service Engine Soon Indicator Illuminated, Transmission Slips, Engine Flare, Delayed 2-3 Shift, Shifts Missing, No Shift, DTCs P0730, P0756, P0757 (Replace Accumulator Assembly/Service Transmission) #03-07-30-005 - (Feb 12, 2003)


2002 Chevrolet Avalanche, Express, Silverado, Suburban

2002 GMC Savana, Sierra, Yukon XL

with 4L80E (MT1) or 4L85E (MN:cool: Automatic Transmission

Built Between February 1, 2002 and April 10, 2002

Condition

Some customers may comment that the Service Engine Soon Indicator is illuminated, the transmission slips, the 2-3 shift takes too long, or the transmission does not shift properly.

Cause

The condition may be due to an improper finish to the bore of the 2-3 accumulator housing, causing damage to the seals.

Correction

Important

Verify the vehicle build date in GMVIS. If the vehicle build date is between February 1, 2002 and April 10, 2002, proceed with this bulletin. If not within the build date, refer to SI for diagnostic procedures.


More, if needed...
 
sperry said:
Here's one:

Malfunction Indicator Lamp (MIL) On, Transmission Stuck in Second or Third Gear, Instrumend Cluster Inoperative (Replace Ignition Switch) #01-07-30-002D - (Oct 19, 2004)

2004-2005 Buick Rainier
1999-2000 Cadillac Escalade
2002-2005 Cadillac Escalade, Escalade EXT
2003-2005 Cadillac ESV
1997-1999 Chevrolet Full-Size Pickup, Suburban, Tahoe (Old Style)
1997-2005 Chevrolet Blazer, Corvette, Express, S-10
1999-2005 Chevrolet Silverado (New Style)
1999-2005 Chevrolet Blazer RH Drive (Export)
2000-2005 Chevrolet Suburban, Tahoe
2002-2005 Chevrolet Avalanche, TrailBlazer, TrailBlazer EXT
2004-2005 Chevrolet Colorado
1997-1999 GMC Sierra, Suburban, Yukon (Old Style)
1997-2001 GMC Jimmy
1997-2005 GMC Savana, Sonoma
1999-2005 GMC Sierra (New Style)
2000-2005 GMC Yukon, Yukon XL
2002-2005 GMC Envoy, Envoy XL
2004-2005 GMC Canyon, Envoy XUV
1997-2004 Oldsmobile Bravada
2004-2005 Pontiac GTO
2003-2005 HUMMER H2

with 4L60-E, 4L65-E, 4L80-E or 4L85-E Automatic Transmission (RPOs M30, M32, M33, MT1, MN:cool:

This bulletin is being revised to update model years, add additional models and 4L80/85 Transmission Information. Please discard Corporate Bulletin Number 01-07-30-002C (Section 07 -- Transmission/Transaxle).

Condition

Some customers may comment on one or more of the following conditions:

* The Malfunction Indicator Lamp (MIL) is ON.
* The transmission is defaulted to second gear (4L80/85-E).
* The transmission is defaulted to third gear (4L60/65-E).
* The instrument cluster is inoperative.

Upon investigation, one or all of the diagnostic trouble codes (DTCs) P0740, P0753, P0758, P0785, P0787, P0973, P0976, P1860, P2761, P2764 and P2769 may be set depending on the vehicle.


Cause

The most likely cause of this condition may be a loss of voltage to the transmission on circuit 1020. This loss of power may be caused by an open in the ignition switch. This condition may also be the result of an incorrect installation of an aftermarket electronic device such as a remote starter or alarm system.

Please Joe, don't throw the codes.

I don't remember what mods you have on your truck, but if it's not some after market stuff, then I'd go with the Ignition guess.

Say the word and we could probably throw a real quick Let's Fix Joe's Avalanche GTG real quick.
 
It's really something else...(as the phrase)

There's a chart for voltage checks they use. Now, given that most of these problems are intermittent, wouldn't one conclude that if the key is worked a bit and functions restore and break on and off, that it just may be that switch? :2:

Oh well....

 
Very interesting info!! It is kind of looking like the ignition switch. I am experiencing some of those other conditions and it's pretty sporadic. Could act funny if I drive to the store to pick up some beer and when I get back to my Av to go home it works fine.

Would love to do a GTG but I'm leaving for the Philippines on 12/22 for 3 weeks so I may just leave it until I get back.
 
Enjoy the trip! You'll be back with enough time to prep for out GTG in Laughlin!

 
MTBJoe said:
Very interesting info!! It is kind of looking like the ignition switch. I am experiencing some of those other conditions and it's pretty sporadic. Could act funny if I drive to the store to pick up some beer and when I get back to my Av to go home it works fine.

Would love to do a GTG but I'm leaving for the Philippines on 12/22 for 3 weeks so I may just leave it until I get back.

Well, that's a relief to know you are going to do anything crazy to the Avalanche. It can't get any worse if you're not using it.

Could you look up some of my Bride's family while you're down there?

I know you'll be meeting the MIL and family for the first time and please take my best wishes to her father when you get there. I remember the situation just after the MEGA Meet. It broke my Bride's heart.

Have a safe trip and let's GTG and fix your truck when you get back!
 
Back
Top