P1641 GMC
Cooling Fan Relay 1 Control Circuit
GMC
P1642 GMC
Fan Control Relay 2 and 3 Control Circuit
P163C GMC
Glow Plug Control Module Primary Circuit
P163D GMC
Glow Plug Control Module Secondary Circuit
P1638 GMC
Generator ‘F’ Terminal Circuit Conditions
P1639 GMC
PCM 5 Volt Reference Voltage Circuit Condition
P1635 GMC
5-Volt Reference Circuit Low Conditions
P1636 GMC
PCM Stack Overrun
P1637 GMC
Generator L-Terminal Circuit
P1633 GMC
Ignition Supply Power Circuit Low Voltage