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Home / DTC / P2148 — Fuel Injector Group A Supply Voltage Circuit High

P2148 — Fuel Injector Group A Supply Voltage Circuit High

Detailed page for trouble code P2148.

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Code

P2148

Generic P — Powertrain

Fuel Injector Group A Supply Voltage Circuit High

Brand: Generic
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Short to battery or other constant voltage source on injector supply wiring
  • Faulty or stuck fuel injector supply relay or fused feed
  • Corroded/loose connector or damaged insulation allowing voltage backfeed
  • Internal PCM/ECM fault (driver/supply transistor failed)
  • Poor or open ground elsewhere causing erroneous voltage reading
  • Aftermarket device or modification tied into injector supply circuit

Symptoms

  • MIL (check engine light) illuminated
  • Possible rough idle or misfire on cylinders in Group A (may or may not be present)
  • Fuel trim abnormalities or drivability issues
  • No-start or hard-start if supply is interrupted elsewhere

What to check

  • Retrieve freeze frame and live data with a scan tool; identify which injectors make up Group A
  • Visually inspect wiring harnesses, connectors and the injector rail for corrosion, damage or pinched wires
  • Check for related fuses and relays; verify relay operation and correct fuse value
  • Backprobe the injector group supply pin at the harness and at the PCM while key ON and with engine running (if safe)
  • Measure battery voltage to establish reference
  • Check for aftermarket accessories or recent repairs on fuel/injector circuits

Signal parameters

  • Battery voltage (static, key ON): ~11–16 V (typical reference 12–14.5 V)
  • Injector supply rail (expected): near battery voltage when feed is unswitched or near PCM-specified level when PCM-controlled; should not exceed battery voltage significantly
  • PCM control signal to injectors: pulsed ground (injector driver) while supply stays near battery; supply should not be pulsed by PCM in most designs
  • Diagnostic indication: controller registers 'HIGH' when measured supply exceeds expected threshold above the vehicle reference (thresholds vary by manufacturer)

Diagnostic algorithm

  1. Read and record DTCs, freeze-frame data and PID values. Note which cylinders are in Group A and any concurrent codes.
  2. Visually inspect injector connectors, wiring harness, and routing for heat, chafing or repairs. Repair obvious damage before further testing.
  3. With ignition ON (engine OFF), measure voltage at the Group A injector supply pin at the harness and compare to battery voltage. Note any voltage significantly above battery or any unexpected sources tied to the circuit.
  4. Verify fuse(s) and relay(s) supplying the injector rail. Remove/inspect relay; measure for unintended continuity or stuck contacts. Replace suspect components.
  5. With a lab scope or scan tool, monitor injector supply and driver signals while cranking/idle (if safe). Look for abnormal steady high voltage or backfeed when drivers should be switching.
  6. Check continuity between injector supply pin and the fuse/relay output and between supply pin and PCM supply input. Look for shorts to battery or to other circuits.
  7. Inspect/verify PCM grounds and chassis grounds related to fuel/injector circuits. Repair low-resistance grounds if found.
  8. If wiring and power devices check good, consider testing or replacing the PCM only after exhausting wiring and component checks (PCM replacement is last resort).
  9. Clear codes and test drive to confirm repair; re-scan to ensure code does not return.

Likely causes

  • Shorted feed wire (pinched/damaged harness) to the fuel injector Group A supply
  • Failed fuel-injector power relay or stuck contacts
  • Blown or incorrect fuse, or fuse bypassed
  • Corroded or loose connector at injector rail or PCM
  • PCM internal fault in the injector supply circuit

Fault status

⚠️ Status
PCM detected higher-than-expected voltage on Fuel Injector Group A supply circuit.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1-3 hours

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Code

P2148

LAND ROVER P — Powertrain

injector group supply voltage A - high circuit voltage

Brand: LAND ROVER
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Short to battery or other constant voltage source on injector supply wiring
  • Faulty or stuck fuel injector supply relay or fused feed
  • Corroded/loose connector or damaged insulation allowing voltage backfeed
  • Internal PCM/ECM fault (driver/supply transistor failed)
  • Poor or open ground elsewhere causing erroneous voltage reading
  • Aftermarket device or modification tied into injector supply circuit

Symptoms

  • MIL (check engine light) illuminated
  • Possible rough idle or misfire on cylinders in Group A (may or may not be present)
  • Fuel trim abnormalities or drivability issues
  • No-start or hard-start if supply is interrupted elsewhere

What to check

  • Retrieve freeze frame and live data with a scan tool; identify which injectors make up Group A
  • Visually inspect wiring harnesses, connectors and the injector rail for corrosion, damage or pinched wires
  • Check for related fuses and relays; verify relay operation and correct fuse value
  • Backprobe the injector group supply pin at the harness and at the PCM while key ON and with engine running (if safe)
  • Measure battery voltage to establish reference
  • Check for aftermarket accessories or recent repairs on fuel/injector circuits

Signal parameters

  • Battery voltage (static, key ON): ~11–16 V (typical reference 12–14.5 V)
  • Injector supply rail (expected): near battery voltage when feed is unswitched or near PCM-specified level when PCM-controlled; should not exceed battery voltage significantly
  • PCM control signal to injectors: pulsed ground (injector driver) while supply stays near battery; supply should not be pulsed by PCM in most designs
  • Diagnostic indication: controller registers 'HIGH' when measured supply exceeds expected threshold above the vehicle reference (thresholds vary by manufacturer)

Diagnostic algorithm

  1. Read and record DTCs, freeze-frame data and PID values. Note which cylinders are in Group A and any concurrent codes.
  2. Visually inspect injector connectors, wiring harness, and routing for heat, chafing or repairs. Repair obvious damage before further testing.
  3. With ignition ON (engine OFF), measure voltage at the Group A injector supply pin at the harness and compare to battery voltage. Note any voltage significantly above battery or any unexpected sources tied to the circuit.
  4. Verify fuse(s) and relay(s) supplying the injector rail. Remove/inspect relay; measure for unintended continuity or stuck contacts. Replace suspect components.
  5. With a lab scope or scan tool, monitor injector supply and driver signals while cranking/idle (if safe). Look for abnormal steady high voltage or backfeed when drivers should be switching.
  6. Check continuity between injector supply pin and the fuse/relay output and between supply pin and PCM supply input. Look for shorts to battery or to other circuits.
  7. Inspect/verify PCM grounds and chassis grounds related to fuel/injector circuits. Repair low-resistance grounds if found.
  8. If wiring and power devices check good, consider testing or replacing the PCM only after exhausting wiring and component checks (PCM replacement is last resort).
  9. Clear codes and test drive to confirm repair; re-scan to ensure code does not return.

Likely causes

  • Shorted feed wire (pinched/damaged harness) to the fuel injector Group A supply
  • Failed fuel-injector power relay or stuck contacts
  • Blown or incorrect fuse, or fuse bypassed
  • Corroded or loose connector at injector rail or PCM
  • PCM internal fault in the injector supply circuit

Fault status

⚠️ Status
PCM detected higher-than-expected voltage on Fuel Injector Group A supply circuit.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1-3 hours

Similar codes

P0200 P0201 P0202 P0203 P0204 P0205
269

Browse 269 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

LAND ROVER

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Code

P2148

MITSUBISHI P — Powertrain

Injector common circuit high

Brand: MITSUBISHI
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Short to battery or other constant voltage source on injector supply wiring
  • Faulty or stuck fuel injector supply relay or fused feed
  • Corroded/loose connector or damaged insulation allowing voltage backfeed
  • Internal PCM/ECM fault (driver/supply transistor failed)
  • Poor or open ground elsewhere causing erroneous voltage reading
  • Aftermarket device or modification tied into injector supply circuit

Symptoms

  • MIL (check engine light) illuminated
  • Possible rough idle or misfire on cylinders in Group A (may or may not be present)
  • Fuel trim abnormalities or drivability issues
  • No-start or hard-start if supply is interrupted elsewhere

What to check

  • Retrieve freeze frame and live data with a scan tool; identify which injectors make up Group A
  • Visually inspect wiring harnesses, connectors and the injector rail for corrosion, damage or pinched wires
  • Check for related fuses and relays; verify relay operation and correct fuse value
  • Backprobe the injector group supply pin at the harness and at the PCM while key ON and with engine running (if safe)
  • Measure battery voltage to establish reference
  • Check for aftermarket accessories or recent repairs on fuel/injector circuits

Signal parameters

  • Battery voltage (static, key ON): ~11–16 V (typical reference 12–14.5 V)
  • Injector supply rail (expected): near battery voltage when feed is unswitched or near PCM-specified level when PCM-controlled; should not exceed battery voltage significantly
  • PCM control signal to injectors: pulsed ground (injector driver) while supply stays near battery; supply should not be pulsed by PCM in most designs
  • Diagnostic indication: controller registers 'HIGH' when measured supply exceeds expected threshold above the vehicle reference (thresholds vary by manufacturer)

Diagnostic algorithm

  1. Read and record DTCs, freeze-frame data and PID values. Note which cylinders are in Group A and any concurrent codes.
  2. Visually inspect injector connectors, wiring harness, and routing for heat, chafing or repairs. Repair obvious damage before further testing.
  3. With ignition ON (engine OFF), measure voltage at the Group A injector supply pin at the harness and compare to battery voltage. Note any voltage significantly above battery or any unexpected sources tied to the circuit.
  4. Verify fuse(s) and relay(s) supplying the injector rail. Remove/inspect relay; measure for unintended continuity or stuck contacts. Replace suspect components.
  5. With a lab scope or scan tool, monitor injector supply and driver signals while cranking/idle (if safe). Look for abnormal steady high voltage or backfeed when drivers should be switching.
  6. Check continuity between injector supply pin and the fuse/relay output and between supply pin and PCM supply input. Look for shorts to battery or to other circuits.
  7. Inspect/verify PCM grounds and chassis grounds related to fuel/injector circuits. Repair low-resistance grounds if found.
  8. If wiring and power devices check good, consider testing or replacing the PCM only after exhausting wiring and component checks (PCM replacement is last resort).
  9. Clear codes and test drive to confirm repair; re-scan to ensure code does not return.

Likely causes

  • Shorted feed wire (pinched/damaged harness) to the fuel injector Group A supply
  • Failed fuel-injector power relay or stuck contacts
  • Blown or incorrect fuse, or fuse bypassed
  • Corroded or loose connector at injector rail or PCM
  • PCM internal fault in the injector supply circuit

Fault status

⚠️ Status
PCM detected higher-than-expected voltage on Fuel Injector Group A supply circuit.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1-3 hours

Similar codes

P0200 P0201 P0202 P0203 P0204 P0205
406

Browse 406 MITSUBISHI manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

MITSUBISHI

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Keep it short and practical. Up to 500 characters.
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