Hey guys I just got my car back from shop. I had a tranny built with new torque converter and a 3 rib 3.42 diff installed. It has 200 miles on the new setup and I went for a small road trip... The torque converter keeps unlocking and will stay unlocked until I clear the code.

I looked up to see what the code is and I can't find it... Will I be safe to drive 70-100 miles home with the converter unlocked?

 

The car is a 98 A4 coupe with 145k miles

 

Was any tunning done after the Gear change?
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DTC P1870 Transmission Component Slipping



DTC P1870 Range Reference Thumbnail 4L60-E Range
Gear
Shift Solenoid
TCC Solenoid
TCC PWM Solenoid
2-4 Band
Forward Clutch
3-4 Clutch
Torque Converter Clutch

1-2
2-3

Overdrive
4th
ON
OFF
ON
90% (ON)
Applied
Applied
Applied
Applied


Circuit Description
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. The table above indicates shift solenoid states and transmission components that apply during 4th gear with the TCC commanded ON.

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 Setting the DTC
DTC P1870 sets if the following conditions are met for three TCC cycles with reported excessive TCC slip conditions, two consecutive times.

No TP Sensor DTCs P0122 or P0123.
No VSS Assy. DTCs P0502 or P0503.
No TCC Sol. Valve DTC P0740.
No 1-2 SS Valve DTC P0753.
No 2-3 SS Valve DTC P0758.
No 3-2 SS Valve Assy. DTC P0785.
No TCC PWM Sol. Valve DTC P1860.
The engine speed is greater than 450 RPM for 5 seconds.
Not in fuel cutoff.
The vehicle speed is 56-105 km/h (35-65 mph).
The speed ratio is 0.67-0.90 (the speed ratio is the engine speed divided by the output speed).
The engine speed is 1200-3500 RPM.
The engine torque is 40-400 lbs ft.
The gear range is D4.
Not in 1st gear.
The TP angle is 10-50%.
The TFT is between 20-130°C (68-266°F).
TCC is commanded On for 5 seconds.
The TCC is at maximum apply for 1 second.
The shift solenoid performance diagnostic counters are zero.
The TCC slip speed is 80-800 RPM.
All conditions met for 7 seconds.

Important
The following actions may occur before the DTC sets.


If the TCC is commanded ON and at maximum apply for 5 seconds, the TP angle is 10-40%, 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 A: If the TCC slip speed is 80-800 RPM for 7 seconds, then the PCM will command maximum line pressure and freeze shift adapts from being updated.
Condition B: If Condition A is met and the TCC slip speed is 80-800 RPM for 7 seconds, then the PCM will command the TCC OFF for 1.5 seconds.
Condition C: If Condition B is met and the TCC slip speed is 80-800 RPM for 7 seconds, then the fail counter on the current ignition cycle is incremented. Two consecutive fail counts are required to set DTC P1870 (type B).
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).
The PCM inhibits TCC engagement.
The PCM commands maximum line pressure.
The PCM inhibits 4th gear if the transmission is in hot mode.
The PCM freezes shift adapts from being updated.
DTC P1870 stores in PCM history.
Conditions for Clearing the MIL/DTC
The PCM turns OFF the MIL after three consecutive trips without a failure reported.
A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported.
The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM.
Diagnostic Aids
Internal transmission failures could set DTC P1870.

 

yup i had ECS do a mail order tune for me.

is it the tune or something wrong with the drivetrain? should i take it back to the guys who did it and have them inspect?

 

help

 

bump...any ideas?

 

...

 

Could be several reasons for the problem.

Did you change rear gear ratios ?

It could be a tune issue or internal issue.

I would get up on a lift and check fluid level, connections, etc ...

You'll also need to contact ECS and discuss the tune they gave you and the code you are receiving.

If these items don't correct the situation you probably have some internal issue.

 

yea i had the tranny rebuilt, new torque converter and a 3 rib 3.42 diff i got from a CF member. i sent the PCM in to ECS to tune it for the new gears...how can i check if the pcm is tuned to the gears? WOT it shifts at 5,500 rpm's now rather than at 6,000 is that normal?

 

The change in gears would require that shift points be adjusted, etc ....

The only way to figure out all of this is with HP Tuners or some other type of Tuning software that would provide what your settings are via data logging or examining the variious shift tables.

The reason it shifts at a lower RPM is probably due to the wrong gear ratio or tire diameter size being used.

Is there a tunning shop near you ?

 

i dont know of any...maybe 1 shop

let me check with ECS

 

Why don't you post on the local boards and see if anyone around you can hook you up and see what's going on with your tune.

ECS is far away from you. You would have to pull and send them your PCM again for a retune.

 

i only know of 3 people from on the forum, locally...i dont think they have one.

 

It never hurts to post up in the local section as you might get lucky.

It seems like you really need a full dyno tune to get everything sorted out.

 

how do i post in local section?

 

Under forums there is a events\regional area. even 2 for California!

http://forums.corvetteforum.com/upco...-discussion-9/

Thats all I got for you, Good Luck !
Jim

 

hmmm thank you!

 

UPDATE

the tranny pump ended up going out...so the shop put a new pump in and new torque converter...they also lowered the tranny line pressure...im still getting the same code...is my valve body toast or is it something else? i really need some help and insight...thank you

 

Any reason why they did not troubleshoot this problem...while they had the car?

 

You really need someone to open the tune and see if the REAR END 3.42's have been added to the tune!

It also need a scan done to see what is really going on!

How did the shop reduce the line pressures? Tech II or some other type of tuning device?

What are some of the surrounding area's in Redding? Are you near Vacaville = Steve @ RSD can help?

I am way to far or I could hook-up my HP Tuner and do a full scan!!!

Did the tranny shop replace the whole Solenoid Pack on your tranny or did they use the old Solenoid pack?

I would ask them for them to show you your old Solenoid pack!!!

Thanks,Matt