Possible causes for the code
RESISTANCE IN THE (A1) BATTERY POSITIVE CIRCUIT
(K20) GENERATOR FIELD CONTROL CIRCUIT OPEN
(K20) GENERATOR FIELD CONTROL CIRCUIT SHORTED TO GROUND
POWERTRAIN CONTROL MODULE (PCM)
The Powertrain control module needs almost 10 volts to work propery, If the battery has less than the needed voltage, the PCM shuts down. When the battery gets enough voltage to run the PCM, the PCM "reboots". When the voltage drops too low, the cycle starts over again. At least take it in and let them test the battery and alternator. Both are covered under the 3/36 warranty. The reason the truck runs bad is the PCM is not working due to low voltage. Also when the PCM "reboots" it needs time to relearn its parameters...It is common for batteries to be bad right off the lot, they sit on the dealers lot for long periods of time without being cranked.
Last edited by Parts/Service; 09-01-2008 at 10:22 PM.