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 MANUALSSATURN2000SC2 AUTOMATIC, MP6REPAIR AND DIAGNOSISENGINE PERFORMANCESYSTEMENGINE CONTROLS - SELF-DIAGNOSTICSDIAGNOSTIC TESTSDTC P1635: 5-VOLT REFERENCE CIRCUITDIAGNOSTIC PROCEDURES
2000 Saturn SC2 Automatic, MP6
Diagnostic Procedures
2000 Saturn SC2 Automatic, MP6SECTION Diagnostic Procedures
NOTE:
A short to battery voltage in 5-volt reference circuit will not set this DTC.
- Turn ignition on, with engine off. Wait 10 seconds. Using scan tool, monitor status of this DTC. If scan tool indicates that DTC P1635 is active, go to next step. If scan tool does not indicate that DTC P1635 is not active, problem is intermittent. See DIAGNOSTIC AIDS .
- Disconnect one sensor at a time while monitoring voltage to another sensor on the 5-volt reference line using scan tool. When one sensor is left connected, reconnect a sensor that was previously disconnected, then disconnect the last sensor. Monitor scan tool voltage reading. If voltage on monitored sensor changes to a normal reading when another sensor is disconnected, replace affected sensor. If voltage on monitored sensor does not change to normal reading when another sensor is disconnected, go to next step.
- Turn ignition off. Disconnect PCM harness connector J1. Check continuity between 5-volt reference circuit and chassis ground and between 5-volt reference circuit and ground circuit at harness connector on each sensor (TP, MAP, EGR and fuel tank pressure sensor). If continuity exists on any of the circuits, repair short in affected circuit. If continuity does not exist on any of the circuits, replace PCM.
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.