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 MANUALSCHEVROLET2020EXPRESS 2500 LS, 4.3L ENG VIN P, GASREPAIR AND DIAGNOSISENGINE PERFORMANCETESTING & DIAGNOSISENGINE CONTROLS AND FUEL - 4.3L (LV1) - DIAGNOSTIC INFORMATION AND PROCEDURES (1 OF 2)DIAGNOSTIC INFORMATION AND PROCEDURESDTC P025A (CHASSIS CONTROL MODULE)CIRCUIT/SYSTEM TESTING
2020 Chevrolet Express 2500 LS, 4.3L Eng VIN P, Gas
Circuit/System Testing
2020 Chevrolet Express 2500 LS, 4.3L Eng VIN P, GasSECTION Circuit/System Testing
- Ignition/Vehicle & All vehicle systems - Off
- Disconnect the electrical connector : K38 Chassis Control Module
- Connect a test lamp between the test points : Control circuit terminal 20 & Ground
- Perform the scan tool control function : Fuel Pump Enable Command @ Engine Control Module - On and Off
Verify the test lamp turns On and Off.
- If the test lamp is always Off
- Ignition/Vehicle - Off & Remove - Test lamp
- Disconnect the electrical connector : K20 Engine Control Module
- Ignition - On / Vehicle - In Service Mode
- Test for less than 1 V between the test points : Control circuit terminal 20 @ K38 Chassis Control Module & Ground
- If 1 V or greater - Repair the short to voltage on the circuit.
- Go to next step : If less than 1 V
- Ignition/Vehicle - Off
- Test for less than 2 ohms between the test points : Control circuit terminal 20 @ K38 Chassis Control Module & The other end of the circuit
- If 2 ohms or greater - Repair the open/high resistance in the circuit.
- If less than 2 ohms - Replace the component : K20 Engine Control Module
- If the test lamp is always On
- Ignition/Vehicle - Off & Remove - Test lamp
- Disconnect the electrical connector : K20 Engine Control Module
- Test for infinite resistance between the test points : Control circuit terminal 20 @ K38 Chassis Control Module & Ground
- If less than infinite resistance - Repair the short to ground on the circuit.
- If infinite resistance - Replace the component : K20 Engine Control Module
- Go to next step : If the test lamp turns On and Off
- Test or replace the component : K38 Chassis Control Module
NOTE:
It may take up to 2 min for all vehicle systems to power down before an accurate ground or low Reference circuit continuity test can be performed.
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.