P06D2
- Powertrain
- Generic (SAE)
- Emissions
Diagnose soon
Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.
Sensor Reference Voltage E Circuit Open
This code is in our catalogue but has not yet been through editorial review, so the guidance below is limited to what our structured data supports. We publish deeper diagnostic content only after a code has been reviewed — here is why.
The 5-volt sensor reference rail E is open — the module supplies no voltage on this circuit. Every sensor powered from reference E loses its supply and reads invalid, so the ECU substitutes default values and may limit engine operation. Causes: a broken reference wire, a disconnected connector, or an internal open in the module's voltage regulator for rail E.
A trouble code records what a control module measured. It does not identify which part failed. Test before replacing anything.
- Safe to drive
- Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.
- Urgency
- Diagnose soon
- Will it pass emissions
- No
- Check engine light
- Solid
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
Many vehicles show no symptom at all beyond the warning light. The absence of a symptom does not mean the fault is not real.
| # | Cause | How often | Component |
|---|---|---|---|
| 1 | Open in shared reference rail | Very common | — |
| 2 | Pin pushed back out of connector body | Occasional | — |
| 3 | Cracked solder joint inside the module or sensor | Occasional | — |
Ordering reflects how often each cause is responsible in general, not a probability for your vehicle. Confirm by testing.
- Sensor Reference Voltage E
- Definition
- Generic code set (SAE J2012 / ISO 15031-6) via the OBDexopen database, dedicated to the public domain under CC0-1.0.
- Diagnostic guidance
- Written and reviewed in-house. See our editorial policy.
- Review status
- Awaiting review
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