P217B

Code

Generic P — Powertrain

Fuel Injector Group G Supply Voltage Circuit Low

Brand: Generic

Type: P — Powertrain

Views: UK: 27 EN: 43 RU: 28

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Page language: EN

Causes

Blown fuse or tripped circuit protecting injector supply
Faulty power/ignition relay feeding injector group
Damaged or corroded connector at injector group power feed
Broken, frayed, or shorted wiring in the injector supply harness
High resistance connection (poor terminal, corrosion) between battery and injector supply
Weak or discharged battery or poor battery terminals

Symptoms

Check Engine MIL/SES lamp on
Rough idle or intermittent misfire on affected cylinders
Reduced engine power or hesitation under load
Hard starting or no-start condition if many injectors are affected
Poor fuel economy
Possible stalling or limp-home behavior

What to check

Read and record all stored DTCs, freeze-frame and live data with a scan tool (note voltage and injector group status).
Inspect fuses and relays for the injector supply circuit; verify relay operation.
Visually inspect wiring harness and connectors for damage, corrosion, heat damage, or pushed-out pins.
Measure battery voltage and verify good battery terminals and ground connections.
Back-probe the injector group power feed with key ON (engine OFF) and while cranking; compare to battery voltage.
Measure injector coil resistance for units in group G and compare to specification.

Signal parameters

Expected injector group supply voltage: ~11.5–14.5 V (key ON / running) — should be near battery voltage
Low-voltage threshold that may set code: typically below ~8–9 V (manufacturer-specific)
Typical injector coil resistance (gasoline): roughly 1–16 Ω depending on low- or high-impedance injectors (consult OEM spec)
Typical injector coil current: short-duration peaks ~0.5–5 A per injector (varies by design)
Continuity: near 0 Ω between supply rail and fused battery positive (with fuses removed as required)

Diagnostic algorithm

Retrieve code P217B and any other related DTCs; record freeze-frame data and live data for injector group supply voltage.
Inspect fuses and the injector/ECM power relay for that circuit. Replace suspect fuse/relay and retest.
Check battery voltage and condition. Clean and tighten battery positive and ground terminals.
Visually inspect the wiring harness and connectors for Fuel Injector Group G (look for corrosion, melted insulation, pin damage, or chafing).
With key ON (engine OFF), back-probe the injector group power feed at the connector and measure DC voltage. It should be close to battery voltage. Note any voltage drop when cranking.
If voltage is low at the connector, isolate sections of the harness: disconnect the connector at the injectors and measure voltage at the harness side and at the supply fuse/relay. This narrows down location of drop or short.
Check continuity between the injector supply pin and battery positive (with circuit de-energized and fuse removed as needed). Check for short to ground by measuring resistance from supply to chassis ground.
Measure each injector coil resistance in group G to detect shorted or open injectors. If a single injector is shorted it can pull the supply down.
Wiggle test wiring while monitoring voltage to reproduce intermittent low-voltage condition.
If wiring and connectors are good and supply at the fuse/relay is correct but the PCM still reports low, inspect PCM power/ground connections. Consider PCM/ECM fault after verifying supply wiring and components.
Repair or replace damaged wiring, connectors, fuses, relays, or faulty injectors as found. Clear codes and perform a road test to confirm repair.

Likely causes

Corroded or loose connector at the injector group power rail
Blown fuse or bad injector power relay
Short to ground on the injector supply circuit (pinched wire)
High-resistance ground or battery terminal leading to voltage drop
Failed PCM power-driver or internal supply/regulator

Fault status

⚠️ Status

Fuel Injector Group G Supply Voltage Circuit Low — the engine control module detected the power feed for injector group G is lower than expected, indicating a supply, wiring, connector, or control module issue.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.5 - 3.0 hours