I have a 1998 Buick Century Custom and I failed inspection for a P1870 code. What is this and how do I fix it? I was told to disconnect the battery for a few hours and this may reset it.
DTC P1870 is a type B code. The conditions for setting the P1870 DTC must occur on TWO CONSECUTIVE TRIPS (ignition cycles, with a drive cycle) before setting a P1870 history code. When the conditions for setting DTC P1870 are met (first trip), the PCM commands maximum line pressure and harsh 1-2 shifts are the result. This may result in a harsh 1-2 shift with no history code if the conditions for setting the DTC required 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 second consecutive trip, a DTC P1870 is stored as a history code. When the P1870 code is stored, the PCM will turn on the Service Engine Soon (SES), Check Engine Light (CEL), or Malfunction Indicator Lamp (MIL). Correction Install a control valve body with the revised TCC regulator and isolator valves. You can try the battery disconnect idea but if it does work it will be temporary.
Search Buick Century Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Buick Century Experts