P1870 Code

[Choppers]

I have this code. Have had it for 3 years and overdrive only works for 5 minutes then after that it quits untill next morning it works again for 5 minutes. Also after like 30 minutes of driving 1-2 shifts are hard. What parts do i need to order to have this fixed. Gas mileage sucks with no overdrive.

[mrhobbz]

Re: P1870 Code

P1870 - Trans. Component Slippage.

Could be a torque converter or tcc valve?

[Archer]

Re: P1870 Code

This is what I pulled up. hope it helps..
Archer


Circuit Description with 4L60-E / 4L65-E Automatic Transmission
The Powertrain Control Module (PCM) monitors the difference between engine speed and transmission output speed. In D3 drive range with the TCC engaged, the engine speed should closely match the transmission output speed. In D4 drive range, with the TCC engaged, the TCC slip speed should be -20 to +40 RPM.

When the PCM detects excessive TCC slip when the TCC should be engaged, then DTC P1870 sets. DTC P1870 is a type B DTC.

CONDITIONS FOR RUNNING THE DTC

• No TP sensor DTCs P0122 or P0123.
• No VSS assembly DTCs P0502 or P0503.
• No TCC solenoid valve DTC P0740.
• No 1-2 SS valve DTC P0753.
• No 2-3 SS valve DTC P0758.
• No 3-2 SS valve assembly DTC P0785.
• No TCC PWM solenoid valve DTC P1860.
• The engine speed is greater than 450 RPM for 5 seconds.
• The engine is not in fuel cutoff.
• The TP angle is 8-35%.
• The engine torque is 40-450 lbs ft.
• The vehicle speed is 48-131 km/h (30-82 mph).
• The speed ratio is 0.65-0.98 (speed ratio is engine speed divided by transmission output speed).
• The engine speed is 1000-3000 RPM.
• The gear range is D4.
• The commanded gear is not 1st gear
• The TFT is between 20-130°C (68-266°F).
• The shift solenoid performance diagnostic counters are zero.
• The TCC is commanded ON for 5 seconds.

CONDITIONS FOR SETTING THE DTC
DTC P1870 sets if the following conditions occur for three TCC cycles.

• The TCC is at maximum duty cycle for 5 seconds. The TCC slip speed is 200-800 RPM for 7 seconds.

IMPORTANT: The following actions may occur before the DTC sets.

• If 4th gear is commanded, the TCC is commanded ON and at maximum duty cycle for 5 seconds , the TP angle is 7-40%, and the transmission slip counter has incremented to either 1 or 2 (out of 3 to increment the fail counter for the current ignition cycle), then the following slip conditions and actions may increment the fail counter for the current ignition cycle:

These conditions must occur sequentially.

• Condition 1: If the TCC slip speed is 200-800 RPM for 7 seconds , then the PCM commands maximum line pressure and freezes shift adapts from being updated.
• Condition 2: If Condition 1 is met and the TCC slip speed is 200-800 RPM for 10 seconds , then the PCM commands the TCC OFF for 1.5 seconds.
• Condition 3: If Condition 2 is met and the TCC slip speed is 200-800 RPM for 15 seconds , then the fail counter on the current ignition cycle is incremented.

The above slip conditions and actions may be disregarded if the TCC is commanded OFF at any time as a result of a driving maneuver (sudden acceleration or deceleration).

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 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 P1870 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.

DIAGNOSTIC AIDS

• Bronze material found in the transmission oil pan may indicate stator shaft bushing wear. If bushing wear is suspected, inspect the stator shaft and the input (turbine) shaft for damage.
• Refer to Symptom Diagnosis for more information. See: Transmission and Drivetrain\Automatic Transmission/Transaxle\Testing and Inspection\Symptom Related Diagnostic Procedures

[sekanda]

Re: P1870 Code

I fixed the P1870 with part 1870V from http://www.transmissioncenter.net/4l60e.htm.

Cost $22 and works great.

Greetings from Vienna
Alex

[Choppers]

Re: P1870 Code

i am really torn whether or not to keep runnig it or fix it. don't have alot of money to spend. car has 157,000 miles

[Choppers]

Re: P1870 Code

what do you guys think put the $22 part in? torque converter works for 5 minutes after startup when cool. i just don't wanna put money into something that might not fix it. i have ran it for 35,000 miles like this.

[dgreet77]

Re: P1870 Code

That part should fix it. I used the same thing and added a shift kit while I had it apart, worked out great. The transgo kit claims to even fix this problem, and it most likely does because it gives you a new valve to replace the one that generally wears, but I used the 1870 fix part in conjunction with the shift kit and it works great, definitely worth it. If you just do the 1870 fix it would be super easy, just drop the valve body and replace the valve, you will be able to see where its worn.

[pace2006]

Re: P1870 Code

I would replace the valve body. Extensive wear from the P1870 code usually results in losing gears, typically starting at 1st and moving up. You've already lost Overdrive. That right there should be enough in repairs. Why wait and have to pay even more later?

[Choppers]

Re: P1870 Code

will my overdrive come back full-time if i replace this? it works like i said when the tranny is cold or for 5 minutes then when you starting shifting gears again its gone. also on that sit theres 2 different 1870 part things. one that is $125 and the other that is $18 for my 96. I just need the cheap part right?

[sekanda]

Re: P1870 Code

You need just the cheap part, the other part is a bigger valve and a reamer.
Are you sure the you loose you overdrive?
Maybe you loose only the TCC (Lockup).

lg.
Alex

[pace2006]

Re: P1870 Code

I can't tell you if it will or not. What you need to do is take it to a transmission shop to be looked over. They should be able to tell you how extensive the damage is and whether you'll need to replace additional parts. When mine started showing symptoms of the P1870 code, I bought the Sonnax valve body kit and had the shop install it. I'm not sure about the part mentioned. If I could go back and do it all again, I would just pick up a TransGo shift kit, which comes with a replacement valve body for much cheaper.

[Choppers]

Re: P1870 Code

well when i get other interstate i feel it shift into 4th then nothnig else happens rpms don't go down anymore. 70 running 2800-3000 rpms. just seems like the torque converter is locking in so the rpms will drop.

[dgreet77]

Re: P1870 Code

I would just pick up a TransGo shift kit, which comes with a replacement valve body for much cheaper.

As far as I know there isn't a shift kit that comes with a whole new replacement valve body, just different parts that go into the valve body. There is a new valve which helps the 1870 code, but not a whole valve body. The cheap part from that site is a replacement for that same valve that comes with the shift kit, so either way would most likely fix the issue if you are only losing the TC lockup.

[Choppers]

Re: P1870 Code

so my torque converter isn't locking up making the rpms run high?

[Choppers]

Re: P1870 Code

i just ordered the valve so we will see if it fixes it.