Archives: DTC Codes

What Does Code P1622 Mean? DTC P1622, “Immobilizer ID Does Not Match,” indicates a critical security system failure where the Powertrain Control Module (PCM), also commonly referred to as the Engine Control Module (ECM) or Engine Management System (EMS), has detected an invalid or non-matching key transponder identification code. The immobilizer system is an integral […]

What Does Code P1623 Mean? DTC P1623, “Immobilizer Code Word/ID Number Write Failure,” indicates a critical issue within the vehicle’s passive anti-theft system (PATS) or similar immobilizer security system. This code is typically set by the Powertrain Control Module (PCM) or Engine Control Module (ECM) when it attempts to store, write, or verify the immobilizer’s […]

What Does Code P1624 Mean? DTC P1624 indicates a malfunction within the vehicle’s Powertrain Control Module (PCM), specifically related to an incorrect or missing signal from the Vehicle Anti-Theft System (VATS) or immobilizer control module. The PCM, also known as the Engine Control Module (ECM) in some applications, expects a unique, verified signal from the […]

What Does Code P1625 Mean? DTC P1625 signifies a “B+ Supply To VCRM Fan Circuit Malfunction.” The Powertrain Control Module (PCM), often referred to as the Engine Control Module (ECM), monitors the electrical integrity of numerous circuits within the vehicle’s powertrain and auxiliary systems. In this specific instance, the PCM has detected an anomalous voltage […]

What Does Code P1626 Mean? DTC P1626 signifies a critical fault within the vehicle’s powertrain control system, typically indicating that the Powertrain Control Module (PCM) has not received the expected “Theft Deterrent Fuel Enable Signal” from the immobilizer system. This signal is a vital digital handshake between the vehicle’s security module (often referred to as […]

What Does Code P1627 Mean? DTC P1627, generically defined as “Module Supply Voltage Out Of Range,” indicates that the Powertrain Control Module (PCM), also referred to as the Engine Control Module (ECM), has detected an abnormal operating voltage supplied to a specific auxiliary control module. This “out of range” condition signifies that the voltage input […]

What Does Code P1628 Mean? The diagnostic trouble code P1628, “Module Ignition Supply Input Malfunction,” indicates that the Powertrain Control Module (PCM), also commonly referred to as the Engine Control Module (ECM), has detected an irregularity or an improper voltage level on one of its dedicated ignition supply input circuits. This circuit provides the PCM […]

What Does Code P1629 Mean? DTC P1629 indicates an detected malfunction within the internal voltage regulator of the alternator, as reported by the Powertrain Control Module (PCM) or Engine Control Module (ECM). The PCM/ECM continuously monitors the vehicle’s charging system voltage, typically targeting a range between 13.2V and 14.8V (specifics vary by manufacturer and operating […]

What Does Code P1630 Mean? The diagnostic trouble code P1630 indicates an Internal Vref Malfunction within the Powertrain Control Module (PCM), also commonly referred to as the Engine Control Module (ECM) or Engine Control Unit (ECU). This code signifies that the PCM has detected an issue with its internally generated 5-volt reference voltage (Vref) circuit. […]

What Does Code P1631 Mean? The OBD-II diagnostic trouble code P1631 indicates a malfunction within the vehicle’s theft deterrent system or an issue with the main power relay, as detected by the Engine Control Module (ECM), also commonly referred to as the Powertrain Control Module (PCM). This code specifically points to either an incorrect “start […]