Question about GMC Sierra 1500

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Gm 4l60e 2-3 shift flares

Pids showing epc amps are 0.7A when shifting 2-3 causing a flare, tried pcm maf and map, no vacuum leaks, im confused the mechanical gadge shows adequate pressure when harness is disconected...

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  • Alexandre Gingras
    Alexandre Gingras Mar 25, 2014

    Its not about shift solenoid, its about epc solenoid (force motor) that control the line pressure... Pcm command low line pressure when its supposed to be high...

  • Vincent Competello
    Vincent Competello Mar 25, 2014

    The pressure is suppose to gradually rise so as not to make the shift too harsh. Does the pressure regulator voltage stay low or does it go to system voltage?

  • Alexandre Gingras
    Alexandre Gingras Mar 25, 2014

    The pids i have are in amps and it goes from 1a to .7a on acceleration and as i learned its supposed to be .1a so the cumputer is not comanding right pressure is a bad engine load can cause this ?

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  • GMC Master
  • 354 Answers

Just a rough explanation. First gear is the low clutch engaged by power to the 1-2 and 2-3 solenoids, second gear applies a band by power to The 1-2 solenoid turned off. Third gear, however, both solenoids have no power. If you are showing power to any solenoids, there is an electrical issue. If the solenoids shut off, the direct clutch is worn and I must say this is very, very common for this clutch to fail.

Posted on Mar 25, 2014

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Posted on Jan 02, 2017

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  • 13 Answers

SOURCE: shift concern on 2002 isusu axiom 4l30 e

the problem of the bump is not the trans.....remove the driveshaft...seperate the slip joint....clean out old grease in there and replace grease and re assemble with a new clamp or heavy zip tie.
ford makes a nice teflon grease.....i have done this repair dozenz of times when i worked at an isuzu dealer.
good luck

Posted on Feb 15, 2009

redbeard00
  • 957 Answers

SOURCE: intermitten hard shift 1-2, 2-3, flare shift into 4th

The trani is electronically controlled. without a diagnostic computer you are not going to know. It may be the speed sensors (for the trani.) but thats a guess. how long since the last trani service. Fluid level and condition can affect its perfomance. Good luck.

Posted on Apr 29, 2009

autotherapis
  • 501 Answers

SOURCE: '03 Z71 1-2 shift slide and 2-3 shift flare. Was

You need to do a pressure check. There is a oil pressure port on the driver side above and to the left of the manual linkage. Put an oil pressure gage in that port. In park and neutral it should sit at 30psi. In reverse it should jump to 210+/-, in drive it will surge as you give it gas up to about 90. If you are not getting this response, suspect either the pressure regulator, or I hate to say it, you may have damaged the pump installing the torque converter. (I owned an AAMCO shop and this would happen at least once a month with guys that did this for a living. It is easy to misaligned the tc when you are installing it.

Hope this helps

Posted on Aug 19, 2009

Transdoc
  • 829 Answers

SOURCE: 2002 Ford Explorer 5R55W transmission had

Band adjustment is very sensitive on these units, I set both adjustments at one turn. This is a 4 speed trans that has been converted to a 5 speed by turning on the od unit ( 1-2 shift ) in first gear.the 2-3 shift is busy because the od band is coming off causing the od unit to transfer back to 1:1 and the intermediate band is coming on . I have found that if the overdrive band is to loose it will release to fast causing a flare on the 2-3 shift bot not really affecting the 4-5 (overdrive) shift. So break both band adjustments loose and tighten the adjustment screw down and back off 1 turn the tighten jam nuts. Also the fluid level should be checked with the transmission warm ( 100 f , not hot, not cold) and the fluid should stream out of the check tube. Transgo makes a really nice vb kit that i use that will help these symptoms.

Posted on Jan 25, 2011

ZJLimited
  • 17970 Answers

SOURCE: '02 ACCORD 1-2 Shift Shudder,

The shift control solenoid externally mounted on the transmission can fail and causes a harsh 1-2 shift. Replacing the shift solenoid and flushisng the transmission with genuine Honda automatic transmission fluid may eliminate harsh shifting characteristics. A broken internal spring can cause the same issue. If the shift control solenoid does not repair the problem, the transmission will have to be replaced.

In both cases (CR-V and the Civic) there is a linear solinoid that can cause the problem or if not then a broken spring inside the transmission that can create the same issue. The cheapest thing to do is to replace the linear solinoid and flush the transmission. If there is no change then the transmission will need to be replaced. The spring is deep inside the transmission and would require complete disassembly for replacement, and it's ususally more cost effective to replace the transmission as a unit.

Honda has issued a bulletin on this issue. As far as I can recall it's been about 50/50 between the spring and the solinoid to repair the problem. Some customers choose to live with the issue due to the cost involved.

Hope helps.

Posted on Jan 25, 2011

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1 Answer

What is causing a 2-3 flare?


slow shifting can be from dirty oil, low pressure from blocked oil filter, faulty servos/solenoids and TCM problems
run the fault codes to see if there are any reported codes

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bad sign that, get it checked, do not allow it to slip.
or it can get worse fast.

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My 1993 chevroler s10 blazer shifts hard from 1-2, and loses vacume at my heat control


Here is a list of commn problems thst cause a hard 1-2 shift. A good transmission shop hould be able to fix this common problem.
Causes of a Hard 1-2 shift
1: #8 check ball not seating on plate properly
2: DTC's such as 1870 or any DTC that can cause the PCM to default to high line
3: Broken, stuck, damaged, or incorrectly installed 1-2 accumulator spring/piston ... Note Multiple springs available depending on application. Spring location varies with application.
4: Sticking, damaged or incorrectly installed accumulator valve or spring. Accumulator valve bushing installed backwards.
5: Stuck 4-3 sequence valve, 3-4 relay valve or 3-2 downshift valve.
6: Updated calibration http://calid.gm.com/vci/ or http://tis2web.service.gm.com
7: EMI from the alternator. Shudder/hard shift hot
8: MAF/MAP Problems
9: Band material composition or drum finish
10: Faulty pressure control solenoid
11: Stuck AFL valve
12: wiring issues
13: Servo pin length

Apr 07, 2017 | 1993 Chevrolet S-10 Blazer

1 Answer

I haveca 99 ss camaro with the 4l60e transmission. It has all the gears and shifts fine, but if I get on it in first or second gear it feels slugish like its not putting all the power to the ground. It...


May be its not the transmission at all,The only thing that can get close to doing that would be the transmission , Temperature sensor, or Transmission fluid pressure, The PCM uses the temperature sensor to determine shift pattern and to engage and disengage your TCC(trans toruqe convertor) then there is the Trans fluid pressure sensor, but you said sluggish and stop when it get up in RPM . 4L60E. leave the transmission out of the picture, This car has a MAF and a MAP sensor these are two that you need to be questioning, Either of these 2 sensor take in false air especially when you first start out will make the engine run sluggish till it gets in RPM and not always, Then There is the EGR, that if the pintle doesnt seat it will affect both sensor and can open and not close especially at low RPM till it get more RPM. You are a what the call a speed density engine so look for vacuum leaks look at the MAF and see if the air duct is loose and since your there check the air filter, look at the hose of the MAP see if it that has any broken ,or vacuum leaks try these first

Apr 24, 2011 | 1999 Chevrolet Camaro

1 Answer

2002 Ford Explorer 5R55W transmission had intermediate band and servo piston replaced. Shifted OK for 1-2 months, then developed 2-3 shift flare. Servo bores then rebushed. Helped, but still has...


Band adjustment is very sensitive on these units, I set both adjustments at one turn. This is a 4 speed trans that has been converted to a 5 speed by turning on the od unit ( 1-2 shift ) in first gear.the 2-3 shift is busy because the od band is coming off causing the od unit to transfer back to 1:1 and the intermediate band is coming on . I have found that if the overdrive band is to loose it will release to fast causing a flare on the 2-3 shift bot not really affecting the 4-5 (overdrive) shift. So break both band adjustments loose and tighten the adjustment screw down and back off 1 turn the tighten jam nuts. Also the fluid level should be checked with the transmission warm ( 100 f , not hot, not cold) and the fluid should stream out of the check tube. Transgo makes a really nice vb kit that i use that will help these symptoms.

Jan 25, 2011 | 2002 Ford Explorer

1 Answer

Transmission in failsafe code p0108andp0104andp0102andp0101andp0110


P0108 - (Manifold Absolute Pressure/Barometric Pressure Circuit High Input
The MAP (Manifold Absolute Pressure) sensor measures engine manifold negative air pressure. It's usually a three wire sensor: a ground wire, a 5 volt reference wire from the PCM (Powertrain Control Module) to the MAP sensor, and a signal wire that informs the PCM of the MAP sensor voltage reading as it changes. The higher the engine vacuum, the lower the voltage reading. The voltage should range between about 1 volt (at idle) to about 5 volts (WOT wide open throttle).

If the PCM sees the voltage reading from the MAP sensor is greater than 5 Volts, or if the voltage reading is higher than what the PCM considers normal under certain circumstances, a P0108 DTC will set.

Symptoms of a P0108 DTC code may include:
* MIL (Malfunction Indicator Lamp) will likely be on
* Engine may run poorly
* Engine may not run at all
* Fuel mileage may decrease
* Presence of black smoke at exhaust

Potential causes of a P0108 code:
* Bad MAP sensor
* Leak in vacuum supply line to MAP sensor
* Engine vacuum leak
* Short on signal wire to PCM
* Short on reference voltage wire from PCM
* Open in ground circuit to MAP
* Worn engine causing low vacuum

Possible Solutions:
A good way to diagnose if the MAP sensor is to blame would be to compare the KOEO (key on engine off) MAP sensor reading on a scan tool with the Barometric pressure reading. They should be the same because they both measure atmospheric pressure.

If the MAP reading is greater than 0.5 volt off of the BARO reading, then replacing the MAP sensor would likely fix the problem. Otherwise, start the engine and observe the MAP reading at idle. It should normally be about 1.5 volts (varies according to altitude).

a. If it is, the problem is likely intermittent. Check all the vacuum hoses for damage and replace as necessary. You can also try wiggle testing the harness and connector to reproduce the problem.
b. If the scan tool MAP reading is more than 4.5 volts, check the actual engine vacuum reading with the engine running. If it is less than 15 or 16 in. Hg, then the PCM is probably not seeing enough vacuum (due to a worn engine, perhaps) for a given operating condition (which causes a higher than normal voltage signal to the PCM) and setting the code. Repair the engine vacuum problem and retest.
c. But, if the actual engine vacuum reading is 16 in. Hg or more, then unplug the MAP sensor. The scan tool MAP reading should indicate that there is no voltage present. Check that the ground from the PCM is intact and also that the MAP sensor connector and terminals are tight. If the connection is good, then replace the map sensor.
d. However if, with KOEO, & the MAP sensor unplugged, the scan tool shows a voltage reading, then there may be a short in the harness to the MAP sensor. Turn the ignition off. At the PCM unplug connector and remove the MAP signal wire from the connector. Re-attach the PCM connector and see if with KOEO, the scan tool MAP reading shows voltage. If it still does, replace the PCM. If not, check for voltage on the signal wire you just removed from the PCM. If there is voltage on the signal wire, find the short in the harness and repair.


P0104 - Mass Air Flow (MAF) Circuit Intermittent
Basically this means that there is a problem with the Mass Air Flow High (MAF) sensor or circuit. A more technical description would be that the MAF is producing incorrect air flow readings. Other MAF sensor circuit DTC trouble codes are P0100, P0101, P0102, and P0103.

Symptoms: You will likely not notice any serious drivability problems, although there may be symptoms such as a general decrease in power or sluggishness.

Causes: A code P0104 may mean that one or more of the following has happened:
* The mass air flow (MAF) circuit is incomplete (broken / frayed wire, etc.)
* There is an air leak in the intake system

Possible Solutions: The simplest thing to do is to reset the code and see if it comes back. Then start with the cheapest, easiest repair procedures:
* Verify that the Mass Air Flow Sensor wiring is connected properly and that there are no broken / frayed wires.
* Inspect for any air leaks near the MAF sensor.
* Check the voltage of the MAF sensor (refer to a repair manual for vehicle specific information)
* Replace the MAF sensor.



P0102 - Mass Air Flow (MAF) Circuit Low Input
Basically this means that there is a problem with the Mass Air Flow (MAF) sensor or circuit. A more technical description would be that the MAF circuit had lower than expected voltage (air flow). Other MAF sensor circuit DTC trouble codes are P0100, P0101, P0103, and P0104.
Symptoms: You will likely not notice any serious drivability problems, although there may be symptoms such as a general decrease in power or sluggishness.

Causes: A code P0102 may mean that one or more of the following has happened:
* The MAF may be disconnected, or a wiring connection may be bad
* The MAF may be dirty or otherwise contaminated (Note: if you use a reusable oiled air filter, be careful not to apply too much oil or that can contaminate the MAF).
* The MAF sensor may be faulty
* The vehicle computer may be faulty (very rare)

Possible Solutions: The simplest thing to do is to reset the code and see if it comes back. Then start with the cheapest, easiest repair procedures:
* Verify that the Mass Air Flow Sensor wiring is connected properly and that there are no broken / frayed wires.
* Inspect for any air leaks near the MAF sensor.
* Take the MAF out and clean it using a spray cleaner such as brake cleaner or electrical contact cleaner. Be gentle with the sensor.
* Check the voltage of the MAF sensor (refer to a repair manual for vehicle specific information)
* Replace the MAF sensor.




P0101 - Mass Air Flow (MAF) Circuit Range/Performance Problem
Basically this means that there is a problem with the Mass Air Flow (MAF) sensor or circuit. The PCM detects that the actual MAF sensor frequency signal is not within a predetermined range of the calculated MAF value for more than 4.0 seconds. Other MAF sensor circuit DTC trouble codes are P0100, P0102, P0103, and P0104.

Symptoms: You will likely not notice any serious drivability problems, although there may be symptoms.

Possible Solutions: The simplest thing to do is to reset the code and see if it comes back. Then start with the cheapest, easiest repair procedures:
* Inspect for the following conditions:
An incorrectly routed harness--Inspect the harness of the MAF sensor in order to verify that it is not routed too close to the following components:
- The secondary ignition wires or coils
- Any solenoids
- Any relays
- Any motors
* A low minimum air rate through the sensor bore may cause this DTC to set at idle or during deceleration. Inspect for any vacuum leaks downstream of the MAF sensor.
* A wide open throttle (WOT) acceleration from a stop should cause the MAF sensor g/s display on the scan tool to increase rapidly. This increase should be from 6-12 g/s at idle to 230 g/s or more at the time of the 1-2 shift. If the increase is not observed, inspect for a restriction in the induction system or the exhaust system.
* The barometric pressure (BARO) that is used in order to calculate the predicted MAF value is initially based on the MAP sensor at key ON.
* When the engine is running the MAP sensor value is continually updated near WOT. A skewed MAP sensor will cause the calculated MAF value to be inaccurate. The value shown for the MAP sensor display varies with the altitude. With the ignition ON and the engine OFF, 103 kPa is the approximate value near sea level. This value will decrease by approximately 3 kPa for every 305 meters (1,000 feet) of altitude.
* A high resistance on the ground circuit of the MAP sensor can cause this DTC to set.
* Any loss of vacuum to the MAP sensor can cause this DTC to set.

If you suspect the condition may be related to aftermarket accessories, refer to Checking Aftermarket Accessories in Wiring Systems. Here as an aid in resolving your P0101 trouble code (DTC)...

continue...

Jan 20, 2011 | 2002 Jaguar X-Type

1 Answer

Transmission flares


NO: 43-37
DATE: 2-25-2003
MODEL: MY 2001-2002 S60, V70, V70 XC
SUBJECT: Shift Quality Issues due to B4 Servo Cover Failure, 2-3 upshift harshness or flare
CHASSIS: These chassis breaks are approximate:
S60: 062000-152000
V70: 116000-230000
V70 XC: 036000-067100
TRANSMISSION SERIAL NUMBER: The first 3 digits of the serial number on the affected transmissions will be between 01C (March 2001) and 01L (December 2001).
DESCRIPTION:
In the AW 55-50, brake number four (B4), is only applied in 3rd gear. The B4 is applied by a piston, which is covered by an aluminum cap. This cap has a steel washer crimped to its inside surface, and a rubber cushion that sits between the cover and the washer.
If this washer breaks free from the crimps it will become concaved because of the B4 piston return spring pressure.
This loose washer can cause: - " 2-3 upshift flare / slip - " Harsh 2-3 upshifts - " 3-4 upshift flare / slip - " Harsh 4-3 downshifts
Replacing the broken B4 cover with a new one (PN 30651771) will remedy these symptoms.

Feb 04, 2010 | 2002 Volvo S60

1 Answer

Reset code trailer towing may set code gm 4l60E


Diagnostic trouble code P1870 (Transmission Component Slippage) is a General Motors-specific code whose set parameters are determined by transmission type and engine size. The PCM monitors and compares engine speed to vehicle speed after the converter clutch has been commanded ON in either high gear or Overdrive. Should the expected rpm ratio exceed predetermined parameters, DTC 1870 sets. And upon doing so, the PCM elevates the transmission main line pressure and stops converter clutch apply.

Once the vehicle has made it to a cruise state, the PCM then begins to monitor the vehicle's cruise ratio. If at some point the transmission begins to slip, P1870 sets and line pressure is elevated in an attempt to stop any further slippage and prevent further damage. This would explain why DTC 1870 Ls often accompanied by a complaint of a hard 1-2 up shift.

When this code sets, it could have any number of causes, ranging from the sump running low of fluid to a malfunctioning torque converter. Take a GM 4L60-E transmission, for example. When it's in Overdrive, the forward clutch and the 3-4 clutches are applied, as well as the 2-4 band. Now add the converter clutch. This is what the PCM monitors at cruise. If the ratio breaks away, the cause could be any of three components, the hydraulics that operate them or the electronics that control them. Fortunately, experience has shown that in most cases, the cause can be traced to some form of converter clutch failure as a result of valve body concerns. With GMs 4L80-E transmission, this code has usually been the result of a cracked converter clutch piston.

Put a line pressure gauge ($55 shipped on Ebay, or visit a local trans shop) on the pressure test port and go for a drive to verify proper line pressure. Base pressure at idle in P,N,OD should be around 70psi and around 140psi in R. Max line pressure should be at least 190psi at WOT in 1st or 2nd, 225psi is optimum. If base pressure is low, trans or pump is worn out. If max pressure is low, check EPC solenoid. If reverse is slow to engage, and line pressure does not come up to at least 130psi in reverse, replace the boost valve with a Transgo 0.049" - 0.500" boost valve (easy fix in pan), and replace the servo with an upgrade servo from a Corvette 4L60E. This will give you a more firm shift and address the DTC 1870 which is common to a weaken Boost valve or faulty EPC valve.

Jan 07, 2010 | 1999 Chevrolet Astro

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