P1634high severityPowertrain
Ignition 1 Power Circuit Low Voltage
on 2010 Cadillac Escalade EXT 6.2L V8 · 4WD
What this code means
The PCM detected low voltage on the Ignition 1 power supply circuit.
Symptoms
- Check Engine Light
- Engine stalling
- Erratic gauges
- Multiple system malfunctions
Common causes
- Faulty ignition switch
- Blown Ignition 1 fuse
- Corroded connections
- Damaged wiring in ignition circuit
Diagnostic steps
- Test Ignition 1 circuit voltage at PCM
- Check Ignition 1 fuse
- Test ignition switch
- Inspect wiring and connectors
Repair notes
Check fuse and ignition switch. Repair wiring as needed.
🔌 Don't have a code reader?
Any of these will read and clear this code — pick by how deep you want to go.
Bluetooth code reader (~$25)
Veepeak OBDCheck BLE →
Pairs with your phone — reads and clears codes, live data.
Serious DIY (~$100)
BlueDriver Pro →
Enhanced codes (ABS, airbag, TPMS) plus repair reports.
Shop-grade tablet (~$300+)
Autel MaxiCOM MK808S →
Bidirectional tests, service resets, all systems.
As an Amazon Associate, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1