Code PM_a038 was reported by the “Pedal monitor” controller in the car. The letter “a” in the middle places it among entries of the alert type.
The Pedal Monitor — independent supervision of the accelerator pedal and torque. It makes sure the car only accelerates when the driver actually asks it to. Being a safety function, its codes lead to reduced power.
The most common type. The car logged the event and may have shown it on the screen. The range is wide — from something trivial that clears itself to something that needs attention.
This is how the fault is named inside the car's firmware. For codes without a description it is the most precise clue there is — the name itself says what the event is about.
The text below comes from Tesla's technical documentation. We leave it in the original English so that translation cannot shift its meaning.
Pedal Monitor Warning: Master/Slave Torque Sign is Inconsistent.
The safety monitor will disable innhibit torque production for the remainder of the drive cycle.
Pedal Monitor Warning: Accumulated Torque.
Pedal Monitor Warning: iBooster (Brake Assist) node is MIA on CAN for one or multiple messages
Pedal Monitor Warning: Inconsistent Autopark state.
The safety monitor sets this condition when state follower behavior of the autopark feature is deemed implausible.
The safety monitor will disable the autopark feature for the remainder of the drive cycle.
Pedal Monitor Warning: Pre-watchdog expired.
This condition is set the watchdog GPIO pin is set, indicating an immediate watchdog reset is imminent. This alert is intended to collect diagnostic information only.
This alert will clear immediately.
This alert provides an imminent warning of a likely watchdog reset event.
Pedal Monitor Warning: VCFRONT CAN node is missing.
The safety monitor sets this condition when CAN communication from VCFRONT is considered irrational or missing.
VCFRONT is considered not communicating on CAN for remainder of drive cycle.
Pedal Monitor Warning: Torque Detected in non-torque producing gear.
Pedal Monitor Warning: HVP CAN node MIA
Pedal Monitor Warning: PMF CAN node is missing.
The safety monitor sets this condition when CAN communication from PMF is considered irrational or missing.
This alert will clear when PMF CAN data is received.
PM system is unable to determine PMF state.
Pedal Monitor Warning: Reset for unintended reason.
This condition is set when this ECU powers on and detects an abnormal reset condition from the previous power cycle (for example, from a watchdog timeout).
This alert will clear within one minute of setting.
Pedal Monitor Warning: DAS CAN node is missing.
The safety monitor sets this condition when CAN communication from DAS is considered irrational or missing.
DAS is considered not communicating on CAN for remainder of drive cycle.
Pedal Monitor Warning: UI CAN node is missing.
The safety monitor sets this condition when CAN communication from UI is considered irrational or missing.
UI is considered not communicating on CAN for remainder of drive cycle.
Pedal Monitor Warning: PMR CAN node is missing.
The safety monitor sets this condition when CAN communication from PMR is considered irrational or missing.
This alert will clear when PMR CAN data is received.
PM system is unable to determine PMR state.
Pedal Monitor Warning: Peripheral Register Configuration Error.
This condition is set when a the GPIO register of the ECU reports a configuration error, intended to be a diagnostic alert only.
Pedal Monitor Warning: PM Gear Mismatch.
The safety monitor sets this condition when gear stalk requests intepreted by the drive inverter are considered implausible.
The safety monitor may automatically shift gear to neutral or potentially escalate to inhibiting torque production when detected.
Pedal Monitor Warning: DIF CAN node MIA
PM is not receiving required feedback CAN messages from DIF
PM receives required feedback CAN messages from DIF
Pedal Monitor Warning: Stability Control causes unintended deceleration.
Pedal Monitor Warning: PM and GTW config is Inconsistent.
The safety monitor sets this condition when the drive inveter component configuration mismatches with the platform configuration.
Pedal Monitor Warning: ECC Protection anamoly detected.
This condition is set when ECC protection detected a flash fetch or RAM read error, intended to be a diagonstic alert only.
Pedal Monitor Warning: DI CAN node is missing.
The safety monitor sets this condition when CAN communication from DI is considered irrational or missing.
DI is considered not communicating on CAN for remainder of drive cycle.
Pedal Monitor Warning: GTW CAN node is missing.
The safety monitor sets this condition when CAN communication from GTW is considered irrational or missing.
GTW is considered not communicating on CAN for remainder of drive cycle.
Pedal Monitor Warning: Brake Pedal Error.
This condition sets when BLS NO and NC circuits are considered implausible.
This alert will clear when brake line switch (BLS) is considered plausible.
Pedal Monitor Warning: Cross Check Failed.
Copy it exactly, letter and number included. Photographing the screen is safest — codes often differ by a single digit, and mixing them up leads somewhere else entirely.
Some codes clear after a screen restart or after the car sits locked for a few hours. If the code does not come back, it was usually a one-off glitch.
A one-off entry and a code that appears after every drive are two different things. It helps a service centre enormously if you know exactly when it shows up.
With airbags, brakes, steering and high voltage there is no point waiting it out. With the other groups you can watch and see whether the code returns at all.
Error codes are only part of the picture. For cars on TesList you also see battery health pulled straight from the vehicle, plus a price calculator that works out from current listings what a given car is actually worth today.