Engine Management and Sensors

The control module, its sensor supplies and grounds, and the signals it uses to reason about everything else. A single failed five-volt reference can set half a dozen unrelated-looking sensor codes at once, which is why shared supplies are checked before individual sensors.

743 codes · 9 components · 24 live parameters

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Components

Live parameters to watch

PID	Parameter	Unit	Conversion
01:00	Supported PIDs 01–20 A bitmask telling the scan tool which of PIDs 01 to 20 this vehicle actually supports. Scan tools query this first, which is why two vehicles show different parameter lists.	—	Bit-encoded
01:01	Monitor status since codes cleared Warning lamp state, the number of stored codes, and which readiness monitors have completed. This is the parameter an emissions test reads to decide whether the vehicle is even testable.	—	Bit-encoded
01:04	Calculated engine load Current airflow as a proportion of peak available airflow. The single most useful parameter for judging whether other readings make sense — a fuel trim figure means nothing without knowing the load it was measured at.	%	A × 100 / 255
01:0C	Engine speed Engine speed, derived from the crankshaft position signal. An erratic or dropping value with the engine running steadily is strong evidence of a crankshaft sensor or reluctor problem rather than anything to do with fuelling.	rpm	((256 × A) + B) / 4
01:1C	OBD standards conformance Which OBD standard the vehicle conforms to. Determines which modes and monitors to expect, and explains why some parameters are simply absent on a given vehicle.	—	Enumerated
01:1F	Run time since engine start Seconds since the engine started. Useful context for freeze frame data — a fault stored three seconds after startup means something quite different from one stored after forty minutes.	s	(256 × A) + B
01:21	Distance travelled with warning lamp on How far the vehicle has been driven with the warning lamp illuminated. Honest history: it reveals whether a fault is new or has been ignored for months, which matters when judging secondary damage.	km	(256 × A) + B
01:30	Warm-ups since codes cleared Completed warm-up cycles since the last clear. Together with distance since cleared, this reveals whether codes were erased recently — including immediately before an emissions test.	count	A
01:31	Distance since codes cleared Distance driven since codes were last erased. A very low value on a vehicle presented for sale or test is worth noticing.	km	(256 × A) + B
01:33	Absolute barometric pressure Atmospheric pressure, used for altitude correction. Should closely match manifold pressure with the engine off — a disagreement there is the basis of the P0069 correlation check.	kPa	A
01:41	Monitor status this drive cycle Which monitors have run during the current drive cycle. Useful when trying to complete readiness for an emissions test — it shows what is still outstanding rather than leaving you to guess at the drive cycle.	—	Bit-encoded
01:43	Absolute load value Load normalised against a fixed reference rather than current conditions, which makes it comparable across vehicles and useful for judging whether an engine is producing what it should.	%	((256 × A) + B) × 100 / 255
01:49	Accelerator pedal position D Pedal position from the first pedal sensor. Distinct from throttle position — comparing pedal demand against throttle response separates a driver-input fault from a throttle actuator fault.	%	A × 100 / 255
01:4A	Accelerator pedal position E The second pedal sensor, on a different voltage slope from the first so that no single failure can misrepresent driver intent.	%	A × 100 / 255
01:4D	Time run with warning lamp on Minutes of engine running with the warning lamp illuminated. Alongside distance with the lamp on, this establishes how long a fault has been tolerated.	min	(256 × A) + B
01:4E	Time since codes cleared Minutes of running since codes were erased.	min	(256 × A) + B
01:5A	Relative accelerator pedal position Pedal position relative to its learned rest point.	%	A × 100 / 255
01:5C	Engine oil temperature Oil temperature, which under sustained load runs considerably hotter than coolant. This is why oil over-temperature can occur with an entirely normal-looking temperature gauge, and why this parameter is worth watching when towing or on track.	°C	A − 40
01:61	Driver's demanded engine torque Torque the driver is requesting, as a percentage of reference torque. Comparing demanded against actual torque is the cleanest way to quantify a limp mode — it shows exactly how much the module is withholding.	%	A − 125
01:62	Actual engine torque Torque the engine is actually producing, as a percentage of reference. Well below driver demand with no stored code often means a boost or fuelling shortfall the module has not yet decided to call a fault.	%	A − 125
01:63	Engine reference torque The reference figure the torque percentages are expressed against, which is what makes them convertible into actual newton metres.	Nm	(256 × A) + B
09:02	Vehicle identification number The VIN as reported by the control module. Worth cross-checking against the VIN on the vehicle: a mismatch indicates a replacement module, which explains configuration faults that no sensor test will find.	—	ASCII
09:04	Calibration identification The software calibration currently loaded. Reveals whether a module has been reprogrammed or aftermarket-tuned — which is directly relevant to overboost, overspeed and knock-related faults, and is otherwise almost impossible to establish.	—	ASCII
09:06	Calibration verification numbers A checksum over the calibration, used to verify the software has not been altered. Some emissions inspections check this against a manufacturer database, so an unexpected value can fail a test on its own.	—	Hexadecimal

Trouble codes

Critical 2

High 262

Moderate 281

Low 47

Information, not instruction

CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.

Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.

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