This error code is a manufacturer-specific trouble code, meaning it does not apply to all vehicles makes. Rather, it applies only to specific vehicle makes, such as GM and Chevrolet. Specification of the definition, troubleshooting, and repairs still vary from one make and model to another.
With the speed of the engine going over rpm for 5 seconds, Fuel Shutoff inactive, throttle angle from 8.
LOOK HERE!!! Trouble Code P1870.....for Harsh 1-2 Shifts.
In some cases, the vehicle may experience harsh shifting from upshift. Typically, vehicles of this have been driven more than 20, mi 32, km before this condition happens. This wear happens in the bore that contains the TCC isolator and regulator valves, which results in poor, or no TCC application.
GM and Chevrolet provide a service bulletin for this trouble code. Diagnosis for this code can vary from model and year of the vehicle. Therefore, it is important to follow the diagnosis process carefully and thoroughly and complete each step. If after following all the steps and the condition remain unresolved, then you can contact your dealer or a licensed technician for further diagnosis. Error Code P is a type B code. The conditions that sets this code must happen in on two consecutive trips ignition cycles, with a drive cycle before setting a P history code.
Remember me. Table of Contents. Subscribe to our mailing list.Diagnostic trouble code P 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 sets.
And upon doing so, the PCM elevates the transmission main line pressure and stops converter clutch apply. This really is an added safety strategy, as the PCM had already monitored the upshifts and determined all was well through those ranges. 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, P sets and line pressure is elevated in an attempt to stop any further slippage and prevent further damage. This would explain why DTC is often accompanied by a complaint of a hard upshift. 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 4LE transmission, for example. When it's in Overdrive, the forward clutch and the clutches are applied, as well as the 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 GM's 4LE transmission, this code has usually been the result of a cracked converter clutch piston. Strategies for delivering power directly from the crankshaft into an automatic transmission have ranged from a purely mechanical connection via a high clutch drum and shaft transmitted through a damper plate assembly, to an actual clutch apply, all taking place inside the torque converter's fluid coupling.
The converter clutch apply method has been the strategy of choice among vehicle manufacturers. This strategy has gone through several changes through the years, and the GM 4LE transmission is a good example of a transmission that has gone through redesigns to accommodate these changes.
The solenoid turned the clutch on and off while the check ball assisted in a controlled apply of the clutch Fig. To enhance converter clutch engagement for improved fuel economy, a pulse width modulated PWM torque converter clutch TCC solenoid was added to the system in Fig. This required a change in the pump assembly and valve body to accommodate the required hydraulics. The acronym PWM is cast into the pump cover for easy identification.
With these changes, the PCM provides a duty cycle to this PWM solenoid, which in turn regulates the pressure in the TCC hydraulic circuit, allowing the torque converter clutch to apply gradually. The amount of slip that occurs during the apply is proportional to the duty cycle Figs. The construction of the PWM solenoid is such that when the solenoid is completely turned off, feed pressure AFL to the solenoid is blocked at the solenoid.Automotive Forums.
Code P again, new valve body already. Previous owner installed reman trans at 70, miles due to "sun gears exploded. Getting hard shifts after mile highway drive. After the second mile trip I get check engine light and code P trans.
Trans oil is clean, not burnt, and no major debris in pan. Still same problem. Says trans fluid is clean, very small amount debris maybe brass found in pan. Same problem P code on after two highway test drives. I understand from reading many internet sites, that this is the proper funtion of the P code setting logic.
Trans shop 1 suggests to change Torque converter, but says he will take a long, 30 minute drive with a scanner before starting, in case something else shows up. Any advice?? Can the scanner really determine which component, such as Torque converter is causing the slip? I just don't want to buy a TC and then come back for the whole tranny rebuild. Code leads to internal lose of transmission pressure. No band aids there. Rebuild or replace it and be done with it. Thanksbut I'm just trying to make a fact-based diagnosis of the problem.
Your advice would make sense only if this if is incorrect, so please correct me if needed. Does P sense crankshaft-to-driveshaft or does it sense transmission-input-shaft to driveshaft?? When slippage is detected, the PCM raises the pressure to try to limit the slippage.
My question is if a high-end scanner is able to provide enough information to determine if the slippage is in the torque converter or if the slippage is in the transmission itself. A typical trans rebuild includes a new Torque converter, so the question is usually not answered was the trans slipping?
The total rebuild solution does not find the source of the problem, and the conventional wisdom of "replace it all" is only to the benefit of the mechanic that was unable to make the diagnosis.
Why spend money on parts that have not failed??? To answer your first question. Yes a good scanner will pinpoint where the slippage is.
But the root cause of slippage is internal transmission pressure leakage. There is a lot of band aids like valve body and converter replacement if the converter is where it is slipping.
But it always goes back to internal pressure leakage as the root cause. And the only long term fix is to fix the internal leakage. Which will take a transmission rebuild or replacement. Good Luck. The following diagnostic tips are provided to assist in accurately repairing the condition. Corporate Bulletin Number A, dated Novemberis intended for vehicles with more than 32, km 20, mi. This wear condition is not the cause of DTC P or P on any model year vehicle built after January 15,or any or newer vehicles as the valve body used on these vehicles has been revised to prevent the wear condition.
This bulletin will help to determine if the DTC is caused by the TCC system or by a slipping internal transmission component such as a clutch or band.
Slip speeds greater than about rpm at steady state driving are caused by a slipping clutch or band. Slip speeds below rpm at steady state driving are usually caused by the TCC not applying but may also be caused by a slipping clutch or band.Meaning of P engine trouble code is a kind of powertrain trouble code and when your car's 'P Check Engine' light comes on, it's usually accompanied by a sinking feeling in the pit of your stomach.
The light could mean a costly problem, like a bad catalytic converter, or it could be something minor, like a loose gas cap. But in many cases, it means at minimum that you'll be visiting the car dealer to locate the malfunction and get the light turned off. Is the fuel pump sometimes not priming when you turn the key to ON II? Start by measuring the fuel pressure and checking whether you have bright white-bluish spark at all four plugs.
The mechanical timing is also something that you should check, as we mentioned above. P code on vehicles with electronically controlled automatic transmissions, the shift solenoid is responsible for actuating the hydraulic circuits to activate clutches or bands that change gears inside the automatic transmission.
Engine trouble codes resource center for all car models. Code Search Please fill the "Code Box" to find engine fault code. Select Abadal Schneider Th. Clubsport Yes! Ways to read engine trouble codes. Ways to clear check engine light on car panel. Check Engine Light Dictionary Ways to clear check engine light on car panel.
4L60E valve body upgrade kit, AKA P1870 "code buster"
P Engine Trouble Code Meaning of P engine trouble code is a kind of powertrain trouble code and when your car's 'P Check Engine' light comes on, it's usually accompanied by a sinking feeling in the pit of your stomach. P Fault Symptoms : Check engine light comes on Engine stalling or misfiring Engine performance issues Car not starting If one of these reasons for P code is occuring now you should check P repair processes.
Now don't ask yourself; What should you do with P code? Check engine light comes on Engine stalling or misfiring Engine performance issues Car not starting. If one of these reasons for P code is occuring now you should check P repair processes. The solution is here :.This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic.
Trouble code P is set when no activity is detected on the bank 2 sensor 2 oxygen sensor circuit. Bank 2 refers to the side of the engine opposite of cylinder number one. Sensor 2 means that it is the second sensor in the exhaust, which is usually after the catalytic converter to monitor its efficiency.
This code means that the powertrain control module has detected a fault in the circuit for the oxygen sensor for bank 2 sensor 2. The Check Engine Light will illuminate to let the owner know that there is a problem with the emissions system. Trouble code P sets when the engine management computer does not detect any activity on the oxygen sensor circuit for bank 2 sensor 2.
The first sensor in the exhaust varies voltage very quickly and the voltage variance is greater.4L60E Transmission Valve Body fix P1870 Transmission Component Slipping trouble code.
The second sensor varies slower and the voltage variance is smaller due to the catalyst in the exhaust. When the computer detects that there is no activity or variance in the voltage it sees this as a problem and sets this error code.
There are no drivability problems typically presented when this code sets other than a potential reduction in fuel economy. As with any oxygen sensor code, I recommend performing a visual check of the oxygen sensor harness to check for any obvious signs of damage.
They are under the vehicle and are susceptible to damage by road hazards. Next, they will check the terminals of the connector for any signs of corrosion or water intrusion.
These will cause the voltage readings to be incorrect and will result in an error code. After, they will check the resistance of the oxygen sensor itself and make sure it is within specifications. If all of these checks turn out okay, it is most likely a faulty oxygen sensor. A quick way to check for this is to monitor the voltage of the sensor with a scan tool and either introduce a vaccum leak or an extra fuel source to the vehicle.
This should change the voltage reading to one extreme or the other for the sensor. If there is no change this confirms that the sensor is not reading correctly. The most common mistake would be replacing the oxygen sensor without performing any diagnostics and then you still have a problem. The next common problem would be be replacing the wrong sensor. Depending on the engine configuration it is possible to get the cylinder banks confused if you do not consult the service information for the vehicle you are working on.
There is no need for concern with the trouble code. There will be no drivability concerns related to this trouble code. However, this trouble code will cause you to fail an emissions test if their test equipment connects to the engine computer to check for codes.
If they run your car on a dyno there is a possibility that your car may pass the test as long as there are no other issues. The most common repair is replacing the faulty oxygen sensor. After that I would say that wiring repairs are the next most common repair for this trouble code. YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at With YourMechanic you can skip the auto shop altogether.
The scan tool may show a DTC P set as a history code. CAUSEThe condition may be due to wear in the control valve body. DTC P is a type B code. When the conditions for setting DTC P are met first tripthe PCM commands maximum line pressure and harsh shifts are the result. This may result in a harsh shift with no history code if the conditions for setting the DTC required for the second trip are not met, on two consecutive trips Ignition cycles, with a drive cycle.
These valves are used in all transmissions produced after January 15, Julian Dateand all of the service parts currently available through GMSPO contain revised TCC regulator and isolator valves. AlsoIf all of the following conditions are true, it is not necessary to Rebuild the transmission or to replace additional transmission components beyond the "Control Valve Body".
Transmission operation is normal before the transmission reaches operating temperature, or before DTC P is set no slips, flares, or missing gears. The torque converter is not blue or overheated.
The transmission fluid is not burned or has no burned odor. The transmission fluid pan contains no abnormal debris clutch material, bronze, brass, or metal fragments. Joined Feb 20, Thanks for the additional info, and from reading this it seems like every 4L60E that i owned had that problem!! Dave D.Hi I have been dealing with this problem for quite some time. The transmission seems to shift perfectly until that P code comes back and then switches to high pressure mode causing the trans to shift real hard in second.
It happens only when your light on the gas. I was trying to pass NYS inspection but couldnt. Passed inspection Completed OBD 2 drive cylces. I have installed a reman valve body with no luck on fixing or band-aiding the problem. I hear that the code is caused by bad brass seals inside the transmission and it needs to be replaced.
Is that true? I dont want to change a trans when it seemingly is ok. I did have a good measure of brass in the pan though along with a bunch of tiny round clear balls. I changed the fuild a couple times to flush it out. Could it be a sensor? There is definately no slipping then because Im not even accerlating. Also definately feels like there is no slipping during acceleration.
Any help would be appreciated to solve this head ache once and for all. It did not work either. Do you. There are many possibilities for causing this code.
With the amount of miles on the vehicle, it makes all of the possibilities, possible. Obviously the valve body and PCM were not the cause, but they were the easiest to eliminate, as the others require transmission removal at a minimum. The clear balls in the pan, that is mysterious, I wonder if they weren't fed down the fill tube.
As far as the debris in the pan, was it black in color? I believe one of the possibilities for cause, was pump bushing wear, those I think were bronze, and that turns up black in the pan. To isolate it to torque converter slippage, you would almost need a scan tool that could monitor TCC slip speed data. There are a couple GM service bulletins that I will send your way.
P0160 OBD-II Trouble Code: 02 Sensor Circuit No Activity Detected (Bank 2 Sensor 2)
Condition Some customers may comment on a harsh upshift and the Check Engine Light or Service Engine Soon indicator is illuminated. Diagnosis Typically, these vehicles will have been driven more than 32, km 20, mi before this condition occurs. The scan tool may show a DTC P set as a history code.
A harsh shift or DTC P, caused by wear in the control valve body, may be difficult to duplicate when the transmission temperature is below 93 C F. Cause The condition may be due to wear in the control valve body. This wear occurs in the bore that contains the TCC isolator and regulator valves, and results in poor, or no, TCC apply. Correction Install a control valve body with the revised TCC regulator and isolator valves.
Refer to the Parts Information table below. These valves are used in all transmissions produced after January 15, Julian Dateand all of the service parts currently available through GMSPO contain revised TCC regulator and isolator valves. Important: If all of the following conditions are true, it is not necessary to rebuild the transmission or to replace additional transmission components beyond the control valve body. The purpose of this bulletin is to provide assistance for technicians that have already completed the DTC P diagnostic table in the Service Manual.
It may be difficult to attain the transmission temperature required to adequately cause the DTC to duplicate. Allow the vehicle to idle to assist in warming the powertrain.