Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / P2147 — supply voltage of group A of the injector - low circuit

P2147 — supply voltage of group A of the injector - low circuit

Detailed page for trouble code P2147.

32,992codes
59brands
10,531generic
22,461specific
All codes P-codes (Powertrain) B-codes (Body) C-codes (Chassis) U-codes (Network/User) Tesla Alerts
Reset
Code

P2147

LAND ROVER P — Powertrain

supply voltage of group A of the injector - low circuit

Brand: LAND ROVER
Type: P — Powertrain
Views: UK: 6 EN: 7 RU: 13
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Low battery or poor battery charging (low system voltage)
  • Blown or corroded fuse supplying injector group
  • Faulty injector supply relay or relay control circuit
  • Damaged, corroded or poor connector at injector supply rail or harness
  • Short to ground or high-resistance connection in the injector supply wire
  • Faulty engine ground(s) or high-resistance ground connection

Symptoms

  • Check Engine Light (MIL) illuminated
  • Rough idle, hesitation or misfire(s)
  • Reduced engine performance or limp-home mode
  • Hard starting or crank/no-start in severe cases
  • Poor fuel economy; occasional surging under load

What to check

  • Read and record freeze-frame and live data with a scan tool; confirm P2147 and any related codes
  • Check battery voltage (key ON, engine OFF and with engine running) and charging system
  • Inspect fuses and relays related to injector supply/powertrain; check fuse continuity
  • Visually inspect injector harnesses, connectors and pins for corrosion, damage or water ingress
  • Backprobe and measure injector supply voltage at group connector with key ON and during cranking
  • Perform voltage drop tests on supply and ground circuits for injectors

Signal parameters

  • Expected injector supply voltage: approximately battery voltage (~11–15 V depending on charge state)
  • Fault threshold: supply significantly below battery voltage (commonly < ~9–10 V) will trigger fault
  • Injector coil resistance: varies by vehicle (refer to service manual); typical gasoline injectors are in low- to high-impedance ranges — check OEM spec
  • Injector control signal: ECM switches injectors to ground; supply should remain steady while pulse signals vary between ~0–battery voltage

Diagnostic algorithm

  1. Use a scan tool: read P2147 and any associated codes; note freeze-frame and operating conditions when fault set.
  2. Verify vehicle battery and charging system are healthy (battery state, charging voltage at idle ~13.5–14.5 V).
  3. Inspect harness/connectors at the injector supply rail and ECM for damage, corrosion or loose terminals; repair as needed.
  4. With key ON (engine OFF) backprobe the injector group supply pin(s) and confirm supply voltage equals battery voltage. If low, trace supply back to fuse/relay/battery.
  5. Check continuity from the injector supply pin to the battery/fuse/relay and perform voltage-drop tests on the positive supply and ground with engine cranking.
  6. Inspect and test related fuse(s) and the injector power/ECM relay; replace if faulty and re-check voltage.
  7. If supply and fuses/relays are good, test for short to ground or high resistance in the supply circuit (disconnect injector group and re-test).
  8. If wiring and external components are good, check ECM power output pins per service manual; compare to known-good values and consider ECM or power module replacement only after excluding harness and supply components.
  9. After repairs, clear codes and perform a test drive to verify the fault does not return.

Likely causes

  • Corroded/damaged connector or wiring to the injector supply rail
  • Blown fuse or failed injector supply relay
  • Low battery/poor charging causing supply below threshold
  • Loose or high-resistance engine/chassis ground
  • ECM or power distribution module fault (less common)

Fault status

⚠️ Status
P2147 — Injector group A supply voltage low. Fault stored in ECM; MIL on. Check supply, fuses/relays, wiring and grounds before replacing ECM.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0-3.0 hours

Similar codes

P0200 P0201 P0202 P0627 P0628 P0300
Workshop Manuals

Repair manuals for LAND ROVER

3

Land Rover Defender 300Tdi — Workshop Manual (1996 model year)

Workshop Manual
Defender 300Tdi Years: 1996 Manual in English 7.5 MB
Short description

Official workshop manual for the Land Rover Defender 300Tdi (from 1996 model year). Contains specifications, adjustment, fault diagnosis and step-by-step repair and overhaul procedures for engine, transmission, axles, suspension, brakes, electrical and body. Intended for dealer workshops and trained technicians.

199,00 UAH
Contents
Key sections:
  • 01 INTRODUCTION
  • 04 GENERAL SPECIFICATION DATA
  • 05 ENGINE TUNING DATA
  • 07 GENERAL FITTING REMINDERS
  • 09 LUBRICANTS, FLUIDS AND CAPACITIES
  • 10 MAINTENANCE
  • 12 ENGINE Tdi
  • - Description and operation
  • - Fault diagnosis
  • - Adjustment
  • - Repair and overhaul procedures
  • 19 FUEL SYSTEM Tdi
Buy

Land Rover Defender Workshop Manual Supplement & Body Repair Manual (1999 & 2002 MY)

Workshop Manual
Defender Years: 1999–2002 Manual in English 7.6 MB
Short description

Workshop Manual Supplement and Body Repair Manual for the Land Rover Defender. Includes general specifications, maintenance schedules, tuning data and step‑by‑step repair procedures for engine, transmission, suspension, brakes, electrical and body repairs. Covers Defender models from 1999 and 2002 model years.

199,00 UAH
Contents
Key sections:
  • 01 - INTRODUCTION
  • - Introduction
  • - Dimensions
  • - References
  • - Repairs and replacements
  • - Poisonous substances
  • - Fuel handling precautions
  • - Synthetic rubber
  • - Recommended sealants
  • - Used engine oil precautions
  • - Accessories and conversions
  • - Wheels and tyres
Buy

Land Rover Range Rover — Electrical Library (LRL 0453ENG, 2002)

Workshop Manual
Manual in English Pages: 494 7.1 MB
Short description

Land Rover Range Rover Electrical Library (LRL 0453ENG). Comprehensive manual covering fuse details, earth points, system descriptions, diagnostics and connector pin-outs for electrical troubleshooting and repair. Intended for technicians and service workshops.

199,00 UAH
Contents
Key sections:
  • 1 INTRODUCTION
  • 1.1 About this document
  • 1.2 Battery voltage
  • 1.3 Electrical precautions
  • 1.4 Battery disconnecting / charging
  • 1.5 Disciplines / greases
  • 1.6 Abbreviations
  • 1.7 HeVAC, sensors abbreviations
  • 1.8 How to use this document
  • 1.9 Connector detail format
  • 1.10 Fault diagnosis
  • 1.11 Wire colour codes
Buy
Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email

Report

Harassment or bullying behavior
Contains mature or sensitive content
Contains misleading or false information
Contains abusive or derogatory content
Contains spam, fake content or potential malware

Block Member?

Please confirm you want to block this member.

You will no longer be able to:

  • See blocked member's posts
  • Mention this member in posts
  • Invite this member to groups
  • Message this member
  • Add this member as a connection

Please note: This action will also remove this member from your connections and send a report to the site admin. Please allow a few minutes for this process to complete.

Report

You have already reported this .