P1351: Ignition Diagnostic Monitor Input Circuit Malfunction (Ford); Camshaft or VVT Sensor Range/Performance (Toyota, Lexus, Audi, VW)
Quick Answer
Not safe to drive
P1351 is a manufacturer-specific code, so its meaning depends on the make. Ford lists it as an ignition diagnostic monitor (IDM) input circuit malfunction. Toyota and Lexus list it as a variable valve timing (camshaft) sensor range or performance fault on the right-hand bank, and Audi and Volkswagen as a camshaft position sensor fault on bank 1. Other makes define it differently, so confirm the definition for your car before ordering parts.
- Severity
- High · Ignition
- Estimated repair cost
- From €65 to €5000+, varies by vehicle
€65 or €5000, depending on your car.
- Replace camshaft position sensor€65–€270
- Timing belt kit, or timing chain job (a chain on a V6 is the top of the range)€300–€5000
A scan shows whether P1351 is really stored on your car, which codes sit next to it and how urgent each one is. You can do this parked, with the ignition on.
A scan needs a Bluetooth OBD2 adapter (Bluetooth LE on iPhone), about €25-60; the built-in demo runs without one. See which adapter to buy
What does P1351 mean?
P1351 is a ignition-related diagnostic trouble code classified as high severity.
What are the symptoms of P1351?
- Check engine light on
- Engine misfire or rough running (Ford ignition meaning)
- Hard starting, or an engine that cranks but does not start
- Loss of power or hesitation under load
- Poor fuel economy
- Rattle or noise from the timing drive on a car with a timing fault
- Cylinder misfire code stored alongside P1351
What causes P1351?
Ford: failing ignition control module (ICM) or a poor connection at the module
: medium
Ford: an engine misfire, such as worn spark plug wires or plugs, that the ignition monitor circuit picks up
: high
Open or shorted wiring between the ignition module and the engine computer
: medium
Toyota, Lexus, Audi and VW: faulty or dirty camshaft position sensor, or damaged wiring and connectors
: high
Variable valve timing system not reaching the commanded angle, for example from dirty oil or a faulty control valve
: medium
Timing belt or chain that has stretched or jumped a tooth, so the camshaft is out of step with the crankshaft
: medium
Engine computer fault (rare)
: low
Is it safe to drive with P1351?
No - address this immediately. Avoid driving further than you need to reach a workshop. Depending on the make, P1351 means an ignition circuit fault with misfires (Ford) or a camshaft or valve timing signal outside its expected range (Toyota, Lexus, Audi, VW). Do not drive at all if the check engine light flashes, the engine runs rough, rattles or loses power, because unburnt fuel can damage the catalytic converter and slipped timing can damage the engine.
How do you diagnose P1351?
- Find out which definition applies to your make before buying anything. A Ford IDM fault and a Toyota, Lexus, Audi or VW camshaft fault need different repairs
- Read all codes and the freeze frame. A cylinder-specific misfire code stored with P1351 points first at that cylinder's plug, wire or coil
- On a Ford with the ignition meaning, inspect the plug wires, plugs and the ignition control module connector for damage, corrosion or a loose fit
- On Toyota, Lexus, Audi or VW, look at the camshaft position sensor, its plug and wiring, then check the oil level and condition if the car has variable valve timing
- A generic reader shows the code, the freeze frame and standard live data such as rpm and coolant temperature. It cannot show camshaft or crankshaft signal values or the valve timing angle; that needs manufacturer-level software
- Listen for a timing rattle on a cold start and check for correct oil pressure. If the cheap checks do not help, have the timing chain or belt position checked before the engine is run further
- Clear the code after the repair and drive a mixed cycle to confirm it does not return
How much does P1351 cost to fix?
| Repair | Parts Cost | Labor Cost | Total Estimate | DIY Difficulty |
|---|---|---|---|---|
| Replace spark plug wires or coil wires (Ford ignition meaning) | €30–€150 | €40–€120 | €70–€270 | Moderate |
| Replace ignition control module | €40–€300 | €50–€200 | €90–€500 | Moderate |
| Replace camshaft position sensor | €25–€120 | €40–€150 | €65–€270 | Moderate |
| Repair wiring or replace the connector pigtail | €10–€50 | €60–€180 | €70–€230 | Moderate |
| Replace VVT solenoid or control valve | €30–€150 | €40–€150 | €70–€300 | Moderate |
| Timing belt kit, or timing chain job (a chain on a V6 is the top of the range) | €240–€1500 | €60–€3500 | €300–€5000 | Professional |
Prices estimated as of October 2026. Costs vary by region, vehicle, and shop.
P1351 on specific vehicles
P1351 on Ford
Ford Bronco 5.8 V8 (1996)
P1351 on Toyota
Toyota Avalon 3.0 V6
Related diagnostic codes
Common questions about P1351
- What does P1351 mean?
- It depends on the make. Ford lists it as an ignition diagnostic monitor (IDM) input circuit malfunction. Toyota and Lexus list it as a variable valve timing (camshaft) sensor range or performance fault on the right-hand bank, and Audi and Volkswagen as a camshaft position sensor fault on bank 1. Look up the definition for your own make.
- What causes P1351 on a Ford?
- Causes listed in a Bronco owner forum are a faulty ignition control module, an engine misfire, an open or shorted wiring harness at the module and a poor electrical connection. In one 1996 Bronco 5.8 case, the code cleared after two bad spark plug wires were replaced.
- What does P1351 mean on a Toyota?
- Toyota and Lexus list it as a variable valve timing (camshaft) sensor range or performance fault on the right-hand bank. The engine computer compares the camshaft and crankshaft sensor signals, and sets the code when the valve timing cannot reach the target angle or the mechanical timing has slipped, for example a timing chain that jumped a tooth or a worn actuator.
- Is it safe to drive with P1351?
- Treat it with caution. With a steady light and the engine running smoothly, a short drive to a workshop is a reasonable risk. If the light flashes, the engine misfires, rattles or loses power, stop driving.
- Can a bad camshaft sensor cause P1351?
- On Toyota, Lexus, Audi and VW, yes, it is one of the first things to check, along with its wiring and connector. If a new sensor does not clear the code, the timing itself should be checked, because the sensor only reports what the camshaft is doing.
- Will a generic OBD2 reader show enough to fix P1351?
- A generic reader will show the code, the freeze frame and standard live data such as rpm and coolant temperature. It cannot show camshaft or crankshaft signal values or the valve timing angle, so that part of the diagnosis needs manufacturer-level software or a workshop scanner.
Read our detailed guides
Sources
- broncozone.com broncozone.com/threads/p1351-trouble-code-idm-circuit-malfunction.24288
- aa1car.com aa1car.com/trouble-codes/ford_codes_p1300-p1499.htm
- tat.net.au tat.net.au/scandata/codes/code-view.php?id=5834
- kbb.com kbb.com/obd-ii/p1351/
- en.wikipedia.org en.wikipedia.org/wiki/Toyota_MZ_engine