What Does P1210 Mean?
P1210 indicates a short to battery positive (B+) in the intake valve solenoid circuit used for cylinder deactivation. The ECM detected abnormally high voltage on the solenoid control line, which means the solenoid may be energized continuously or the circuit is receiving unwanted positive voltage. This prevents proper cylinder deactivation control and may cause the solenoid to overheat.
Common Causes
30%
Wiring harness short to a nearby power source or hot wire
25%
Corroded or cross-contaminated connector allowing voltage bleed-through
20%
Failed cylinder deactivation solenoid with internal short to power
15%
Aftermarket wiring or accessory installation causing circuit interference
10%
ECM internal driver fault holding the output high
Diagnostic Steps
1
Review freeze frame data and check for related cylinder deactivation codes such as P1209, P1221, or P1223.
2
Disconnect the intake valve deactivation solenoid connector and check for voltage present on the control wire with the key on, engine off. No voltage should be present when the solenoid is commanded off.
3
Inspect the wiring harness for the solenoid circuit, looking for areas where it runs near power wires, ignition coil feeds, or other hot circuits that could cause a short to B+.
4
Measure the solenoid coil resistance and check for shorts between the control terminal and the power supply terminal.
5
With the solenoid disconnected, check the ECM output pin to confirm whether the B+ voltage originates from the ECM side (driver fault) or the harness side.
6
Repair any wiring damage found, replace the solenoid if shorted internally, and clear codes to verify the repair.
Estimated Repair Cost
$200 - $800
Parts + labor, varies by vehicle and location
P1210 indicates a short to battery positive (B+) in the intake valve solenoid circuit used for cylinder deactivation. The ECM detected abnormally high voltage on the solenoid control line, which means the solenoid may be energized continuously or the circuit is receiving unwanted positive voltage. T...
The most common cause of P1210 (Intake valves for cylinder shut-off Short to B+) is: Wiring harness short to a nearby power source or hot wire
Typical repair costs for P1210 range from $200 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The engine will operate normally on all cylinders but will not enter fuel-saving cylinder deactivation mode. An unresolved short to B+ can cause the solenoid to overheat or the ECM driver to fail, potentially escalating the repair cost.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1210 to identify the root cause.
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Quick Info
Category
Powertrain
System
Variable Cylinder Management / Cylinder Deactivation
Difficulty
Type
Manufacturer
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