What Does P208D Mean?
The DEF pump control circuit voltage is higher than expected. The PCM detects excessive voltage or a short to power condition in the pump control circuit.
Common Causes
35%
Short to voltage in pump control wiring harness
25%
Damaged pump connector causing cross-circuit short
20%
Failed DEF pump with internal short to power
15%
Chafed wiring rubbing on metal causing intermittent short
5%
Faulty DEF control module or PCM output driver
Diagnostic Steps
1
Step 1: Disconnect DEF pump connector and check for voltage on control circuit with key on
2
Step 2: Inspect wiring harness routing for contact with hot surfaces or sharp edges
3
Step 3: Measure resistance of control circuit to battery voltage with pump disconnected
4
Step 4: Check for water intrusion or corrosion in connectors causing cross-circuit issues
5
Step 5: Wiggle test harness while monitoring circuit voltage to identify intermittent shorts
Estimated Repair Cost
$150 - $1,300
Parts + labor, varies by vehicle and location
The DEF pump control circuit voltage is higher than expected. The PCM detects excessive voltage or a short to power condition in the pump control circuit.
The most common cause of P208D (Reductant Pump Control Circuit High) is: Short to voltage in pump control wiring harness
Typical repair costs for P208D range from $150 to $1,300, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle may derate and enter limp mode after continued operation. DEF system malfunction can lead to failed emissions testing and legal compliance issues.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P208D to identify the root cause.
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Quick Info
Category
Powertrain
System
Selective Catalytic Reduction (SCR) Emissions System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
