P023A

Code

Generic P — Powertrain

Charge Air Cooler Coolant Pump A Control Circuit/Open

Brand: Generic

Type: P — Powertrain

Views: UK: 20 EN: 145 RU: 57

AI status

Completed

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Page language: EN

Causes

Blown fuse or faulty relay for the intercooler coolant pump circuit
Open, corroded, pinched, or disconnected wiring/connectors to the pump
Failed pump motor (stalled or internal open)
Poor or missing ground at pump or control module
Faulty ECM/PCM output driver or software issue
Short to battery or short to ground in the control circuit

Symptoms

Malfunction Indicator Lamp / Check Engine Light illuminated
Intercooler / charge air temperatures higher than normal
Reduced engine performance or turbo protection strategies
No audible pump operation when pump commanded
Possible limp-home mode or derated engine operation

What to check

Verify the DTC with a scan tool and record freeze-frame data
Visual inspection of pump, harness, connectors, and mating terminals for corrosion or damage
Check relevant fuses and relays for continuity and correct operation
Back-probe pump connector to measure supply voltage and control signal while commanding pump with scan tool
Measure pump motor resistance and perform a direct bench or fused 12 V test to confirm motor operation
Perform a wiggle test on wiring while observing signal and pump operation

Signal parameters

Battery feed to pump power pin: ~12 V (key ON, engine OFF)
Ground reference: near 0 V at vehicle chassis ground
Control/drive pin from ECM: typically a low-side switch (pulsed ground) or PWM; duty cycle varies with demand (0–100%)
Pump motor DC resistance (approximate): typically low, e.g. 0.2–5 ohms depending on pump design (check OEM spec)
Expected operating current when running: varies by pump model, commonly 1–10 A (use clamp meter to verify)

Diagnostic algorithm

Connect a scan tool, confirm P023A is present, record freeze-frame and pending codes. Clear code and attempt to re-run to reproduce.
Perform a visual inspection of harness, connector, fuse, and relay for the intercooler pump circuit. Repair obvious damage.
With ignition ON, measure battery voltage at the pump power pin. Verify good ground at pump ground terminal.
Command the pump ON with a capable scan tool while monitoring the control wire. Look for a PWM or ground switching signal from the ECM.
If no control signal but power and ground present at pump, apply a fused 12 V directly to pump to confirm pump motor runs and check current draw. Replace pump if it does not run or draws excessive current.
If pump runs with direct battery but no ECM command, inspect wiring between ECM and pump for opens/shorts; repair as needed. Check relay coil supply and ground.
If wiring and pump are good but no correct control signal from ECM, test ECM output with oscilloscope if available; if output absent or abnormal, consider ECM fault and consult manufacturer service info before replacing ECM.
After repair, clear codes and perform a road/drive cycle and re-check for reappearance of the code.

Likely causes

Blown fuse or failed relay
Connector corrosion or open wire at pump harness
Failed pump motor (no rotation / high resistance)
Grounding fault at pump or harness
ECM output driver failure (if wiring and pump test good)

Fault status

⚠️ Status

Open or failed control circuit detected for Charge Air Cooler Coolant Pump A; pump may not run or be commanded correctly.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-2.5 hours

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