Conditions for Setting the DTC
WARNING: This page is about a different car, the 2003 GMC Sonoma, 2003 GMC Jimmy, 2003 Chevrolet S10 Pickup, and 2003 Chevrolet Blazer. However, it is still accessible from the selected car via links, so may be relevant.
DTC P1870 sets if the following conditions occur for three TCC cycles during the same trip.
- The TCC is commanded ON for 5 seconds.
- The TCC is at maximum duty cycle for 8.5 seconds.
- The TCC slip speed is 300-1,000 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 8.5 seconds, the TP angle is 7-40 percent, 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 200-1,000 RPM for 7 seconds, then the PCM commands maximum line pressure and freezes transmission adapt functions.
- Condition 2: If Condition 1 is met and the TCC slip speed is 200-1,000 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 200-1,000 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.