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.
DTC Descriptors: Notes
2006 Isuzu Ascender S, 5.3 M, 4WDSECTION Notes
WARNING: This page is about a different car, the 2007 GMC Envoy, 2007 Chevrolet TrailBlazer, and 2007 Buick Rainier. However, it is still accessible from the selected car via links, so may be relevant.
- DTC P0685
-
Engine Controls Ignition Relay Control Circuit
- DTC P0689
-
Engine Controls Relay Feedback Circuit Low Voltage
- DTC P0690
-
Engine Controls Relay Feedback Circuit High Voltage
IMPORTANT:
Always perform the Diagnostic System Check - Vehicle
prior to using this diagnostic procedure.
Diagnostic Fault Table
| Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
| Relay Coil B+ | P0685 | P0685 | - | - |
| Relay Switch B+ | P0689 | P0689 | - | - |
| Relay Coil Control | P0685 | P0685 | P0685 | - |
| Relay Ignition Output Ignition 1 Voltage | P0689 | P0689 | P0690 | - |
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.