Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSCHEVROLET2006SUBURBAN C2500, 6.0 UREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 199 (CHARGING SYSTEM)DIAGNOSTIC TESTSDTC P1638: PULSE WIDTH MODULATED SIGNAL OUT OF RANGECONDITIONS FOR SETTING DTC
2006 Chevrolet Suburban C2500, 6.0 U
Conditions For Setting DTC
2006 Chevrolet Suburban C2500, 6.0 USECTION Conditions For Setting DTC
WARNING: This page is about a different car, the 2003 GMC Savana Special, 2003 GMC Savana Camper Special, 2003 GMC Savana, and 2003 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
- 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.
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.