System: Powertrain (P-Code)
SAE Standard (Generic)
Family: EGR Cooler Bypass Driver Overcurrent
Code P2AA5: EGR Cooler Bypass Control Circuit Driver Current/Temperature Too High Bank 1
Diagnostic & Technical Explanation
Code P2AA5 (EGR Cooler Bypass Control Circuit Driver Current/Temperature Too High Bank 1) sets when the driver circuit commanding the EGR cooler bypass valve on the named bank reports current or temperature beyond its safe operating limit, causing the ECM to shut the driver down before it overheats. This differs from a simple open/short fault - it means the driver is working but seeing a resistive load or a partially seized valve motor that draws excessive current. Common causes are a valve motor binding from carbon buildup, a partially shorted motor winding, or a marginal ground connection raising circuit resistance.
First-listed procedure
Rank #1
Inspect EGR cooler bypass valve for carbon binding
Moderate DIY
This is the first procedure in the authored
consideration order, not a measured cause likelihood. Execute it only when its prerequisites
and diagnostic findings support it. Its cost and labor estimates (where known), the step-by-step procedure and the
remaining 2 procedure(s) are in the licensed dataset. Ordering context.
Full family: EGR Cooler Bypass Driver Overcurrent
What this page does not show
This page publishes the fault mechanism and the code index. The licensed dataset adds, for
every one of the 15,886 codes, the full authored repair set (56,729 procedures in total)
with the fields deliberately withheld here:
- Procedures 2..n after the first-listed procedure
- Aftermarket parts cost ranges in USD (
est_parts_cost_min/max_usd)
- Professional labor-hour estimates (
est_labor_hours)
- Step-by-step diagnostic and repair instructions
- Replacement-part mappings and catalog lookups
- 6,637 manufacturer-specific OEM codes across 32 makes ($149 tier)