What is this code???
Instructor
Joined: Jun 2004
Posts: 156
Likes: 0
From: Peoria AZ
P1870 Transmission Component Slipping.
Here is a previous discussion on the error code. I never had this problem I just found some info for you. -Ed
http://forums.corvetteforum.com/show...870&forum_id=1
Here is a previous discussion on the error code. I never had this problem I just found some info for you. -Ed
http://forums.corvetteforum.com/show...870&forum_id=1
Racer
Joined: Jul 2001
Posts: 386
Likes: 0
From: Round Rock, Texas, USA
Here is some info:
DTC P1870 Transmission Component Slipping
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.
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 MAF sensor DTCs P0101, P0102 or P0103.
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 engine torque is 40-400 lbs ft.
The TP angle is 10-50%.
The vehicle speed is 56-131 km/h (35-82 mph).
The speed ratio is 0.67-0.90 (the speed ratio is the engine speed divided by
the transmission output speed).
The engine speed is 1200-3500 RPM.
The gear range is D4.
The commanded gear is not 1st gear.
The TFT is between 20-150°C (68-302°F).
The shift solenoid performance diagnostic counters are zero.
Conditions for Setting the DTC
DTC P1870 sets if the following conditions occur for three TCC cycles.
The TCC is commanded ON for 5 seconds.
The TCC is at maximum duty cycle for 8 seconds.
The TCC slip speed is 80-800 RPM for 7 seconds.
Important
The following actions may occur before the DTC sets.
If the TCC is commanded ON and at maximum duty cycle 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 1: If the TCC slip speed is 80-800 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 80-800 RPM for
7 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 80-800 RPM for
7 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.
DTC P1870 Transmission Component Slipping
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.
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 MAF sensor DTCs P0101, P0102 or P0103.
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 engine torque is 40-400 lbs ft.
The TP angle is 10-50%.
The vehicle speed is 56-131 km/h (35-82 mph).
The speed ratio is 0.67-0.90 (the speed ratio is the engine speed divided by
the transmission output speed).
The engine speed is 1200-3500 RPM.
The gear range is D4.
The commanded gear is not 1st gear.
The TFT is between 20-150°C (68-302°F).
The shift solenoid performance diagnostic counters are zero.
Conditions for Setting the DTC
DTC P1870 sets if the following conditions occur for three TCC cycles.
The TCC is commanded ON for 5 seconds.
The TCC is at maximum duty cycle for 8 seconds.
The TCC slip speed is 80-800 RPM for 7 seconds.
Important
The following actions may occur before the DTC sets.
If the TCC is commanded ON and at maximum duty cycle 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 1: If the TCC slip speed is 80-800 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 80-800 RPM for
7 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 80-800 RPM for
7 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.
