Hombre S Regular Cab 4WD V6-4.3L (1999)
Valve Body: All Technical Service Bulletins
A/T - MIL ON/Harsh 1st - 2nd Gear Upshifts/DTC P1870
SB04-05-S001
Harsh 1-2 Upshift and MIL Illuminated with DTC P1870 Set
Issue Date: January 2004
Affected Vehicles
1997-2000 Hombre (TH) models equipped with 4L60-E automatic transmissions with specific transmission codes as listed in the parts information table.
Service Information
Condition:
Some customers may comment on a harsh 1-2 upshift and the Malfunction Indicator Lamp (MIL) lights up. Typically, these vehicles have been driven
more than 20,000 miles before this condition occurs. The scan tool may show a DTC P1870 set as a history code. A harsh 1-2 shift or DTC P1870, may
be difficult to duplicate when the transmission temperature is below 200°F (93°C).
Possible Cause:
This 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, this result
in poor or non-applicable TCC's.
Important:
^
DTC P1870 is a type B code. The conditions for setting the P1870 must occur on TWO CONSECUTIVE TRIPS (ignition cycles, with a drive cycle)
before setting a P1870 history code.
^
When the conditions for setting P1870 are met (first trip), the PCM commands maximum line pressure and harsh 1-2 upshifts are the result.
^
This may result in a harsh 1-2 shift with no history code if the conditions and or requirements for setting the DTC for the second trip are not met, on
two consecutive trips (ignition cycles, with a drive cycle).
^
When the conditions for setting the DTC are met, on the consecutive trip, a P1870 is stored as a history code.
^
When the P1870 code is stored, the PCM will turn on the Malfunction Indicator Lamp (MIL).
Service Procedure
Follow the procedures in the appropriate service manual and install a control valve body with revised TCC regulator and isolator valves, refer to the
parts information table below. These valves are used in all transmissions produced after January 15, 2000 with specific Transmission Codes as listed in
the parts information table. All service parts currently available contain revised TCC regulator and isolator valves.
NOTE:
Transmission Code can be found on the transmission case (refer to illustration for code location).
Important:
If all of the following conditions are true, it is not necessary to replace additional transmission components beyond the control valve body.
^
Transmission operation is normal before the transmission reaches operating temperature, or before P1870 is set (no slips, flares, or missing gears).
^
The torque converter is not blue or overheated.
