FixVault

Home › Cadillac › 2003 › Escalade EXT › Repair and Diagnosis › Electrical › Charging Systems › Diagnostic Tests › DTC P1638: Pulse Width Modulation Signal Out Of Range › Conditions For Setting DTC

Conditions For Setting DTC

During the ignition ON test, the PCM detects a PWM signal is out of range.
During the RUN test, the PCM detects a PWM signal less then 5 percent for more than 6 seconds.