What Does P1794 Mean?
DTC P1794 signals a fault in the direct battery power supply circuit to the Powertrain Control Module. The PCM is detecting an abnormal voltage level on its direct battery feed line, which bypasses the ignition switch. This circuit is critical for maintaining adaptive memory and keep-alive values when the ignition is off.
Safety Warning
An unstable PCM power supply can cause erratic engine operation, stalling, no-start conditions, or loss of adaptive memory leading to poor drivability and potential sudden loss of engine power.
Common Causes
30%
Blown PCM battery feed fuse or fusible link
25%
Corroded or loose battery cable connections
20%
Damaged wiring between the battery and PCM power input
15%
Poor ground connection at the PCM
10%
Internal PCM power supply circuit failure
Diagnostic Steps
1
Check battery voltage with a multimeter; ensure it is 12.4V or higher with the engine off and 13.5–14.7V while running.
2
Inspect and test the PCM direct battery feed fuse and fusible link for continuity.
3
Measure voltage at the PCM battery direct power input pin with a wiring diagram reference; it should match battery voltage at all times.
4
Inspect and clean the battery terminals, ground straps, and PCM ground connections.
5
Trace the wiring from the battery fuse box to the PCM connector and check for chafed, broken, or corroded sections.
Estimated Repair Cost
$50 - $600
Parts + labor, varies by vehicle and location
DTC P1794 signals a fault in the direct battery power supply circuit to the Powertrain Control Module. The PCM is detecting an abnormal voltage level on its direct battery feed line, which bypasses the ignition switch. This circuit is critical for maintaining adaptive memory and keep-alive values wh...
The most common cause of P1794 (Powertrain Control Module Battery Direct Power Circuit) is: Blown PCM battery feed fuse or fusible link
Typical repair costs for P1794 range from $50 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
An unstable PCM power supply can cause erratic engine operation, stalling, no-start conditions, or loss of adaptive memory leading to poor drivability and potential sudden loss of engine power.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1794 to identify the root cause.
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Quick Info
Category
Powertrain
System
Engine Management / Electrical
Difficulty
Type
Manufacturer
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