DTC P1870 Transmission Component Slipping 2.2L
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 +60 RPM. Refer to the
Range Reference
table for 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. |
| • | The vehicle speed is 56-105 km/h (35-65 mph). |
| • | The speed ratio is 0.64-0.95 (the speed ratio is the engine
speed divided by the output speed). |
| • | The engine speed is 1500-3500 RPM. |
| • | The engine torque is 40-450 lbs ft. |
| • | The TP angle is 12-50%. |
| • | The TFT is between 20-130°C (68-266°F). |
| • | The TCC is commanded On for 5 seconds. |
| • | The TCC is at maximum duty cycle for 5 seconds. |
| • | The shift solenoid performance diagnostic counters are zero. |
| • | The TCC slip speed is 300-1000 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 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 200-1000 RPM for 7 seconds,
then the PCM will command maximum line pressure and freeze shift adapts from
being updated.
Condition 2
If Condition 1 is met and the TCC slip speed is 200-1000 RPM
for 7 seconds, then the PCM will command the TCC Off for 1.5 seconds.
Condition 3
If Condition 2 is met and the TCC slip speed is 200-1000 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.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests
the torque converter for slippage while in a commanded lock-up state.
DTC P1870 Transmission Component Slipping (2.2L)
Step
| Action
| Value(s)
| Yes
| No
|
1
| Was the Powertrain On-Board Diagnostic (OBD) System Check
performed?
| --
|
Go to Step
2
| Go to
Powertrain On Board Diagnostic (OBD) System Check
|
2
| Perform the transmission fluid checking procedure. Refer to
Transmission Fluid Check
.
Did you perform the fluid checking procedure?
| --
|
Go to Step 3
| Go to
Transmission Fluid Check
|
3
|
- Install the Scan Tool
.
- With the engine OFF, turn the ignition switch to the RUN position.
Important: Before clearing the DTC(s), use the scan tool in order to record the
Freeze Frame and Failure Records for reference. Using the Clear Info function
will erase the stored Freeze Frame and Failure Records from the PCM.
- Record the DTC Freeze Frame and Failure Records, then clear the DTC(s).
- Drive the vehicle in 4th gear with the TCC commanded ON.
Is the TCC Slip Speed within the specified range for 7 seconds?
| 300-1000 RPM
|
Go to Step 4
| Go to Diagnostic Aids
|
4
|
- Inspect the Torque Converter Clutch Solenoid Valve (TCC Sol. Valve)
for the following conditions:
| • | Internal malfunction (such as sediment or damage) |
- Inspect the Torque Converter Clutch Pulse Width Modulation Solenoid
Valve (TCC PWM Sol. Valve) for the following conditions:
| • | Internal malfunction (such as sediment or damage) |
Did you find a condition?
| --
|
Go to Step 13
|
Go to Step
5
|
5
|
- Inspect the 1-2 Shift Solenoid Valve (1-2 SS Valve) for the following
conditions:
| • | Internal malfunction (such as sediment or damage) |
- Inspect the 2-3 Shift Solenoid Valve (2-3 SS Valve) for the following
conditions:
| • | Internal malfunction (such as sediment or damage) |
Did you find a condition?
| --
|
Go to Step 13
|
Go to Step
6
|
6
| Inspect the valve body assembly
for a stuck TCC signal valve.
Did you find a condition?
| --
|
Go to Step 13
|
Go to Step
7
|
7
| Inspect the torque converter
assembly for the following conditions:
| • | Stator roller clutch not holding |
Did you find a condition?
| --
|
Go to Step 13
|
Go to Step
8
|
8
| Inspect the oil pump assembly
for the following conditions:
| • | Stuck converter clutch valve |
| • | Converter clutch valve assembled backwards |
| • | Mispositioned converter clutch valve retaining ring |
| • | Mispositioned pump to case gasket |
| • | Restricted orifice cup plugs |
| • | Damaged orifice cup plugs |
| • | Over-tightened, or unevenly tightened pump body to cover bolts |
Did you find a condition?
| --
|
Go to Step 13
|
Go to Step
9
|
9
| Inspect the input housing and
shaft assembly for the following conditions:
| • | Cut turbine shaft o-ring seal |
| • | Damaged turbine shaft o-ring seal |
| • | Restricted turbine shaft retainer and ball assembly |
| • | Damaged turbine shaft retainer and ball assembly |
Did you find a condition?
| --
|
Go to Step 13
|
Go to Step
10
|
10
| Inspect the 2-4 band assembly
for the following conditions:
| • | The band anchor pin is not engaged. |
| • | Restricted apply passages in the 2-4 servo assembly |
| • | Blocked apply passages in the 2-4 servo assembly |
| • | Nicks or burrs on the servo pin |
| • | Nicks or burrs on the pin bore in the case |
| • | Damaged fourth servo piston |
| • | Misassembled fourth servo piston |
| • | Incorrect band apply pin |
| • | Damaged servo bore in the case |
| • | Porosity in the pistons |
| • | Damaged piston seal grooves |
| • | Plugged orifice cup plug |
| • | Missing orifice cup plug |
Did you find a condition?
| --
|
Go to Step 13
|
Go to Step
11
|
11
| Inspect the forward clutch assembly
for the following conditions:
| • | Porosity in the forward clutch piston |
| • | Damaged forward clutch piston |
| • | Missing forward clutch piston inner and outer seals |
| • | Cut forward clutch piston inner and outer seals |
| • | Damaged forward clutch piston inner and outer seals |
| • | Missing input housing to forward clutch housing o-ring seal |
| • | Cut input housing to forward clutch housing o-ring seal |
| • | Damaged input housing to forward clutch housing o-ring seal |
| • | Damaged forward clutch housing |
| • | Damaged forward clutch housing retainer and ball assembly |
| • | Forward clutch housing retainer and ball assembly is not sealing. |
Did you find a condition?
| --
|
Go to Step 13
|
Go to Step
12
|
12
| Inspect the 3-4 clutch assembly
for the following conditions:
| • | Porosity in the 3-4 clutch piston |
| • | Damaged 3-4 clutch piston |
| • | Missing 3-4 clutch inner and outer seals |
| • | Cut 3-4 clutch inner and outer seals |
| • | Damaged 3-4 clutch inner and outer seals |
| • | Damaged 3-4 clutch spring assembly |
| • | Damaged 3-4 clutch apply ring |
| • | Damaged piston seal grooves |
| • | Plugged orifice cup plug |
| • | Missing orifice cup plug |
Did you find a condition?
| --
|
Go to Step 13
| Go to Diagnostic Aids
|
13
| In order to verify your repair, perform the following procedure:
- Select DTC.
- Select Clear Info.
- Operate the vehicle under the following conditions:
| • | Drive the vehicle in D4, with the TCC ON, and a throttle position
of 15-50%. |
| • | Ensure that the TCC Slip Speed is -20 to +60 RPM
for at least 7 seconds. |
- Select Specific DTC. Enter DTC P1870.
Has the test run and passed?
| --
| System OK
|
Go to Step 1
|
DTC P1870 Transmission Component Slipping 4.3L
Circuit Description
The Vehicle Control Module (VCM) 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 +50 RPM. Refer to the
Range Reference
table for solenoid states and transmission components that
apply during 4th gear with the TCC commanded ON.
When the VCM 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 TFT Sensor DTCs P0711, P0712 or P0713. |
| • | No TCC Sol. Valve DTC P0740. |
| • | No 1-2 SS Valve DTC P0753. |
| • | No 2-3 SS Valve DTC P0758. |
| • | No TFP Val. Position Sw. DTC P1810. |
| • | No TCC PWM Sol. Valve DTC P1860. |
| • | The engine speed is greater than 450 RPM for 5 seconds. |
| • | The vehicle speed is 48-112 km/h (30-70 mph). |
| • | The engine speed is 1500-3000 RPM. |
| • | The speed ratio is 0.69-0.88 (speed ratio is engine speed
divided by the output speed). |
| • | The engine torque is 50-400 lb ft. |
| • | The engine vacuum is 0-150 kPa. |
| • | The TFT is 20-130°C (68-266°F). |
| • | The shift solenoid performance diagnostic counters are zero. |
| • | The TCC is ON for 5 seconds. |
| • | The TCC is at maximum duty cycle (95%) for 5 seconds. |
| • | The TCC slip speed is 130-800 RPM. |
| • | All conditions met for 7 seconds. |
Action Taken When the DTC Sets
| • | The VCM illuminates the Malfunction Indicator Lamp (MIL). |
| • | The VCM inhibits TCC engagement. |
| • | The VCM commands maximum line pressure. |
| • | The VCM inhibits 4th gear if the transmission is in hot mode. |
| • | The VCM freezes shift adapts from being updated. |
| • | DTC P1870 stores in VCM history. |
Conditions for Clearing the MIL/DTC
| • | The VCM turns OFF the MIL after three consecutive trips without
a failure reported. |
| • | A scan tool can clear the DTC from the VCM history. The VCM clears
the DTC from the VCM history if the vehicle completes 40 warm-up cycles without
a failure reported. |
| • | The VCM cancels the DTC default actions when the fault no longer
exists and the ignition is OFF long enough in order to power down the VCM. |
Diagnostic Aids
Internal transmission failures could set a DTC P1870.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests the torque converter for slippage while in a commanded
lock-up state.
DTC P1870 Transmission Component Slipping (4.3L)
Step
| Action
| Value(s)
| Yes
| No
|
1
| Was the Powertrain On-Board
Diagnostic (OBD) System Check performed?
| --
|
Go to Step
2
| Go to
Powertrain On Board Diagnostic (OBD) System Check
|
2
| Perform the transmission fluid checking procedure.
Refer to
Transmission Fluid Check
.
Did you perform the fluid checking procedure?
| --
|
Go to Step 3
| Go to
Transmission Fluid Check
|
3
|
- Install the Scan Tool
.
- With the engine OFF, turn the ignition switch to the RUN position.
Important: Before clearing the DTC(s), use the scan tool in order to record the
Freeze Frame and Failure Records for reference. Using the Clear Info function
will erase the stored Freeze Frame and Failure Records from the VCM.
- Record the DTC Freeze Frame and Failure Records, then clear the DTC(s).
- Drive the vehicle in 4th gear with the TCC commanded On.
Is the TCC Slip Speed within the specified range for 7 seconds?
| 130-800 RPM
|
Go to Step 4
| Go to Diagnostic Aids
|
4
|
- Inspect the Torque Converter Clutch Solenoid Valve (TCC Sol. Valve)
for the following conditions:
| • | Internal malfunction (such as sediment or damage) |
- Inspect the Torque Converter Clutch Pulse Width Modulation Solenoid
Valve (TCC PWM Sol. Valve) for the following conditions:
| • | Internal malfunction (such as sediment or damage) |
Did you find a condition?
| --
|
Go to Step
13
|
Go to Step 5
|
5
|
- Inspect the 1-2 Shift Solenoid Valve (1-2 SS Valve) for
the following conditions:
| • | Internal malfunction (such as sediment or damage) |
- Inspect the 2-3 Shift Solenoid Valve (2-3 SS Valve) for
the following conditions:
| • | Internal malfunction (such as sediment or damage) |
Did you find a condition?
| --
|
Go to Step
13
|
Go to Step 6
|
6
| Inspect the valve body assembly for a stuck TCC signal valve.
Did you find a condition?
| --
|
Go to Step
13
|
Go to Step 7
|
7
| Inspect the torque converter assembly for the following conditions:
| • | Stator roller clutch not holding |
Did you find a condition?
| --
|
Go to Step
13
|
Go to Step 8
|
8
| Inspect the oil pump assembly for the following conditions:
| • | A stuck converter clutch valve |
| • | The converter clutch valve is assembled backwards |
| • | A mispositioned converter clutch valve retaining ring |
| • | A mispositioned pump to case gasket |
| • | Restricted orifice cup plugs |
| • | Damaged orifice cup plugs |
| • | Over-tightened, or unevenly tightened pump body to cover bolts |
Did you find a condition?
| --
|
Go to Step
13
|
Go to Step 9
|
9
| Inspect the input housing and shaft assembly for the following conditions:
| • | Cut turbine shaft O-ring seal |
| • | Damaged turbine shaft O-ring seal |
| • | Restricted turbine shaft retainer and ball assembly |
| • | Damaged turbine shaft retainer and ball assembly |
Did you find a condition?
| --
|
Go to Step
13
|
Go to Step 10
|
10
| Inspect the 2-4 band assembly for the following conditions:
| • | The band anchor pin is not engaged. |
| • | Restricted apply passages in the 2-4 servo assembly |
| • | Blocked apply passages in the 2-4 servo assembly |
| • | Nicks or burrs on the servo pin |
| • | Nicks or burrs on the pin bore in the case |
| • | Damaged fourth servo piston |
| • | Misassembled fourth servo piston |
| • | Incorrect band apply pin |
| • | Damaged servo bore in the case |
| • | Porosity in the pistons |
| • | Damaged piston seal grooves |
| • | Plugged orifice cup plug |
| • | Missing orifice cup plug |
Did you find a condition?
| --
|
Go to Step
13
|
Go to Step 11
|
11
| Inspect the forward clutch assembly for the following conditions:
| • | Porosity in the forward clutch piston |
| • | Damaged forward clutch piston |
| • | Missing forward clutch piston inner and outer seals |
| • | Cut forward clutch piston inner and outer seals |
| • | Damaged forward clutch piston inner and outer seals |
| • | Missing input housing to forward clutch housing O-ring seal |
| • | Cut input housing to forward clutch housing O-ring seal |
| • | Damaged input housing to forward clutch housing O-ring seal |
| • | Damaged forward clutch housing |
| • | Damaged forward clutch housing retainer and ball assembly |
| • | Forward clutch housing retainer and ball assembly is not sealing. |
Did you find a condition?
| --
|
Go to Step
13
|
Go to Step 12
|
12
| Inspect the 3-4 clutch assembly for the following conditions:
| • | Porosity in the 3-4 clutch piston |
| • | Damaged 3-4 clutch piston |
| • | Missing 3-4 clutch inner and outer seals |
| • | Cut 3-4 clutch inner and outer seals |
| • | Damaged 3-4 clutch inner and outer seals |
| • | Damaged 3-4 clutch spring assembly |
| • | Damaged 3-4 clutch apply ring |
| • | Damaged piston seal grooves |
| • | Plugged orifice cup plug |
| • | Missing orifice cup plug |
Did you find a condition?
| --
|
Go to Step
13
| Go to Diagnostic Aids
|
13
| In order to verify your repair, perform the following procedure:
- Select DTC.
- Select Clear Info.
- Operate the vehicle under the following conditions:
| • | Drive the vehicle in D4, with the TCC ON, and a throttle position
of 9-35%. |
| • | Ensure that the TCC Slip Speed is -20 to +50 RPM
for at least 7 seconds. |
- Select Specific DTC. Enter DTC P1870.
Has the test run and passed?
| --
| System OK
|
Go to Step
1
|
