P2633

Code

LAND ROVER P — Powertrain

Fuel pump B control - low circuit

Brand: LAND ROVER

Type: P — Powertrain

Views: UK: 12 EN: 20 RU: 16

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Page language: EN

Causes

Blown fuse for fuel pump circuit
Faulty fuel pump relay or control module
Damaged, chafed or shorted wiring in pump B control circuit
Corroded or loose connector at fuel pump or driver module
Failed fuel pump motor (internal short) or pump driver
Poor ground connection

Symptoms

Check Engine Light or MIL illuminated
Engine cranks but won’t start (no/low fuel pressure)
Intermittent or complete loss of engine power or stalling
Extended cranking times
Possible unusual battery drain or blown fuse

What to check

Confirm code P2633 and capture freeze-frame/occurrence data
Scan for additional related DTCs (fuel pump, fuel pressure, wiring)
Visual inspection of pump B wiring, connectors and harness for damage or corrosion
Check fuel pump fuse(s) and relay(s) for correct operation
Measure battery voltage at vehicle and at pump connector with key ON and while cranking
Backprobe pump control circuit and monitor voltage while PCM commands pump on

Signal parameters

Battery voltage at vehicle battery: ~12.4–14.5 V (engine running)
Expected voltage at pump positive terminal when commanded ON: near battery voltage (~11–14 V)
Low-circuit indication: control voltage much lower than battery (typically
Expected pump current draw (typical in-tank pumps): several amps (commonly 4–15 A) — refer to vehicle-spec sheet for exact value
Resistance of pump motor (approx): low ohms; open/high resistance indicates open circuit, very low with excessive current may indicate internal short

Diagnostic algorithm

Verify DTC and read freeze-frame data. Note conditions (ignition ON, cranking, speed).
Inspect fuses and relays for the fuel pump circuit; replace or swap known-good relay to test.
Visually inspect wiring harness from fuse/relay/PCM to pump B for damage, rubbing, or corrosion. Repair any damaged insulation or connectors.
With connector exposed, backprobe the pump power and ground pins. With ignition ON and/or PCM commanding pump, measure voltage at the connector. If voltage is near battery, pump supply is OK.
If voltage at connector is low (
Measure pump current while commanded ON. If current is abnormally high or low, suspect pump motor or wiring fault. Apply direct 12 V to pump briefly (bench or harness) to confirm pump operation.
Check ground integrity: measure resistance from pump ground to chassis/battery negative. Repair poor grounds.
If wiring and pump test good, test/replace fuel pump driver module or PCM output driver according to manufacturer procedure. Reprogram/relearn if required after replacement.
Clear codes and perform road/test cycle to confirm repair. Re-scan for reoccurrence and related codes.

Likely causes

Connector at in-tank pump corroded, causing low voltage under load
Control transistor in PCM/fuel pump driver shorted to ground
Wire insulation rubbed through and shorting to chassis ground
Fuse or relay contacts failed, low supply to pump when commanded
Pump motor drawing excessive current causing voltage drop

Fault status

⚠️ Status

PCM detected low-voltage/short-to-ground on Fuel Pump B control circuit when pump was commanded ON. Fuel delivery may be reduced or interrupted.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-3.0 hours

Repair manuals

Manual library for LAND ROVER

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P2633 — Fuel pump B control - low circuit