Code
P0612
Generic
P — Powertrain
Fuel Injector Control Module Relay Control
Views:
UK: 13
EN: 16
RU: 18
AI status
Completed
Completed
100%
Causes
- Blown or corroded fuse for FICM or relay circuit
- Failed FICM relay (stuck open or shorted)
- Open, shorted, or corroded wiring/connectors between PCM, relay, and FICM
- Low battery voltage or poor battery/charging system (voltage out of range)
- Poor ground(s) at PCM, relay, or FICM module
- Water intrusion or connector corrosion at FICM/relay
Symptoms
- Check Engine Light (MIL) illuminated
- Engine may crank but not start or no injector pulse
- Intermittent or complete loss of fuel injector operation
- Engine misfires, rough idle, or poor performance
- Reduced power or stalling
- Possible hard starting or no-crank condition if relay also affects starter/PCM power
What to check
- Read stored codes and freeze-frame data with a scan tool; note accompanying codes and battery voltage
- Visually inspect fuse(s), relay, wiring harness, and connectors for damage, corrosion, or water intrusion
- Check battery voltage at key ON and during cranking (should be ~12–14.5 V)
- Verify continuity and resistance of relay coil and relay control wiring between PCM and relay
- Backprobe relay control pin while commanding relay with scan tool to observe switching voltage
- Check power supply and ground circuits at the FICM for proper voltage and low resistance to ground
Signal parameters
- Battery voltage at FICM power pin: approximately 12–14.5 V (key ON/run)
- Relay control circuit idle: 0–0.5 V or near battery voltage depending on design; when energized should switch (observe change) — expect a clear switched state
- Relay coil resistance (typical range): tens to a few hundred ohms (consult vehicle spec)
- Injector pulse presence: on-time pulses measured by noid light or scope when engine cranks/runs
- Control current to relay coil: typically 0.1–1.0 A depending on relay design
Diagnostic algorithm
- Confirm the code and note freeze-frame (voltage, RPM, engine conditions). Scan for related codes (injector, power, ground, communications).
- Check battery voltage and charging system. Repair low-voltage issues before proceeding.
- Inspect and test fuses and the FICM relay. Replace relay if suspect; re-check for code. Perform a relay swap with identical relay if available.
- With key ON (engine off), backprobe the relay control terminal and command the relay ON with a scan tool or jumper to observe switching. Verify the PCM is commanding the control circuit when expected.
- If PCM does not command relay when expected, trace the control wire from PCM to relay for open/short/poor connection. Repair wiring/connectors as needed.
- If PCM commands relay but relay does not energize, confirm relay coil supply and ground. Replace relay and re-test.
- Verify power and ground at the FICM when relay is energized. If the FICM receives power but injectors not driven, diagnose FICM module or injector driver circuitry.
- After repairs, clear codes and perform test drive or run conditions that previously set the code to confirm the fault is resolved.
- If wiring, relay and FICM check good but code returns, consider PCM/ECM internal driver fault and refer to manufacturer procedures for PCM testing/replacement.
Likely causes
- Failed or intermittent FICM relay
- Open/short in the relay control wire from PCM to relay coil
- Blown fuse supplying FICM power or relay coil
- Weak battery/charging causing relay to drop out
- Corroded connector or poor ground on FICM power/ground circuit
Fault status
Status
PCM detected an open/short or abnormal condition on the Fuel Injector Control Module relay control circuit; relay not being properly controlled.
Repair difficulty: Medium
Diagnostic time: 0.5-3.0 hours
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Code
P0612
LAND ROVER
P — Powertrain
Fuel injector control module relay control circuit
Views:
UK: 5
EN: 8
RU: 8
AI status
Completed
Completed
100%
Causes
- Blown or corroded fuse for FICM or relay circuit
- Failed FICM relay (stuck open or shorted)
- Open, shorted, or corroded wiring/connectors between PCM, relay, and FICM
- Low battery voltage or poor battery/charging system (voltage out of range)
- Poor ground(s) at PCM, relay, or FICM module
- Water intrusion or connector corrosion at FICM/relay
Symptoms
- Check Engine Light (MIL) illuminated
- Engine may crank but not start or no injector pulse
- Intermittent or complete loss of fuel injector operation
- Engine misfires, rough idle, or poor performance
- Reduced power or stalling
- Possible hard starting or no-crank condition if relay also affects starter/PCM power
What to check
- Read stored codes and freeze-frame data with a scan tool; note accompanying codes and battery voltage
- Visually inspect fuse(s), relay, wiring harness, and connectors for damage, corrosion, or water intrusion
- Check battery voltage at key ON and during cranking (should be ~12–14.5 V)
- Verify continuity and resistance of relay coil and relay control wiring between PCM and relay
- Backprobe relay control pin while commanding relay with scan tool to observe switching voltage
- Check power supply and ground circuits at the FICM for proper voltage and low resistance to ground
Signal parameters
- Battery voltage at FICM power pin: approximately 12–14.5 V (key ON/run)
- Relay control circuit idle: 0–0.5 V or near battery voltage depending on design; when energized should switch (observe change) — expect a clear switched state
- Relay coil resistance (typical range): tens to a few hundred ohms (consult vehicle spec)
- Injector pulse presence: on-time pulses measured by noid light or scope when engine cranks/runs
- Control current to relay coil: typically 0.1–1.0 A depending on relay design
Diagnostic algorithm
- Confirm the code and note freeze-frame (voltage, RPM, engine conditions). Scan for related codes (injector, power, ground, communications).
- Check battery voltage and charging system. Repair low-voltage issues before proceeding.
- Inspect and test fuses and the FICM relay. Replace relay if suspect; re-check for code. Perform a relay swap with identical relay if available.
- With key ON (engine off), backprobe the relay control terminal and command the relay ON with a scan tool or jumper to observe switching. Verify the PCM is commanding the control circuit when expected.
- If PCM does not command relay when expected, trace the control wire from PCM to relay for open/short/poor connection. Repair wiring/connectors as needed.
- If PCM commands relay but relay does not energize, confirm relay coil supply and ground. Replace relay and re-test.
- Verify power and ground at the FICM when relay is energized. If the FICM receives power but injectors not driven, diagnose FICM module or injector driver circuitry.
- After repairs, clear codes and perform test drive or run conditions that previously set the code to confirm the fault is resolved.
- If wiring, relay and FICM check good but code returns, consider PCM/ECM internal driver fault and refer to manufacturer procedures for PCM testing/replacement.
Likely causes
- Failed or intermittent FICM relay
- Open/short in the relay control wire from PCM to relay coil
- Blown fuse supplying FICM power or relay coil
- Weak battery/charging causing relay to drop out
- Corroded connector or poor ground on FICM power/ground circuit
Fault status
Status
PCM detected an open/short or abnormal condition on the Fuel Injector Control Module relay control circuit; relay not being properly controlled.
Repair difficulty: Medium
Diagnostic time: 0.5-3.0 hours
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