P1335 — EGR Position Sensor Minimum/Maximum Stop Performance — 6.0 Power Stroke

Diagnostic reference for 6.0 Power Stroke (2003.5–2007) EGR position sensor stop performance fault.

Updated October 15, 2026

What it means

Ford enhanced code — the EGR valve position sensor reading at the valve’s fully closed or fully open stop is outside the expected range. On the 6.0L this is usually a soot-fouled or sticking EGR valve that will not seat or travel fully; often seen alongside P0404.¹

Most likely causes

1. Soot-fouled / sticking EGR valve preventing full closed/open travel — Carbon buildup on valve stem and pintle keeps the valve from reaching the minimum/maximum stop the PCM expects; the position sensor reports an out-of-range stop. Often co-occurs with P0404.¹²
2. EGR position sensor internal fault or wiring/connector degradation — Sensor signal drifts or opens/shorts; connector oil/heat damage or chafed harness causes the PCM to see an invalid stop voltage.¹
3. EGR valve mechanical binding from debris or damaged actuator — Physical obstruction or worn actuator linkage prevents full travel to the stop, so the position sensor never reaches the calibrated limit.¹

How to diagnose

1. Verify code and freeze frame; confirm P1335 is present and note accompanying EGR codes such as P0404 or P0401.
2. Inspect EGR valve connector and wiring for heat damage, oil contamination, and secure pin engagement; repair wiring faults before condemning the valve.
3. Command EGR valve position with a scan tool and monitor EGR Position PID; check that the valve reaches the commanded % and that the minimum and maximum learned stops are within spec.
4. Remove and inspect the EGR valve for soot buildup on pintle, seat, and stem; check for free movement by hand and for carbon packing in the valve bore.
5. If the valve sticks or the position sensor output is erratic at the stops, clean the valve and passages or replace the EGR valve assembly; relearn EGR position per Ford procedure.
6. After repair, clear codes and road test under conditions that set EGR operation; confirm P1335 does not return and that related EGR codes remain cleared.

Common mistake to avoid

Replacing the EGR valve without testing it. If the valve still moves freely, a carbon cleaning often fixes the flow code; and if it opens on command but the code stays, the blockage is in the passages or cooler, not the valve. Source: FleetRabbit — EGR valve problems and repair.

Parts and tools you may need

• Scan tool with bi-directional EGR control and live data
• Digital multimeter
• EGR valve cleaning solvent and soft brushes
• Torque wrench
• Safety gloves and eye protection

Tools you’ll need

• OBD-II scan tool with bi-directional control — Commands EGR valve position and monitors EGR Position PID to verify the valve reaches learned min/max stops for P1335.
• Digital multimeter — Checks EGR position sensor supply, signal, and ground voltages and wiring continuity to rule out electrical faults.

Rough cost and difficulty

Typical US independent-shop figures; labor runs about $120–$180 per hour (dealers charge more). Confirm the diagnosis before buying parts.

When to see a pro

If the EGR valve is seized, the EGR cooler shows signs of coolant loss/white steam, or the vehicle exhibits drivability issues, have a qualified diesel technician inspect the EGR system and related cooling system components. On the 6.0L, EGR cooler failure is often caused by a clogged engine oil cooler.

Check for recalls

Recalls are tied to your truck’s VIN, so check yours directly: enter the VIN at NHTSA’s recall lookup. Open safety recalls are repaired free at a dealer.

Sources