P045D: EGR B Control Circuit High

Exhaust gas recirculation (EGR) routes part of the exhaust back into the intake to lower combustion temperature and NOx. EGR B is a second EGR valve next to valve A – on diesels with two EGR circuits the low-pressure valve, which takes exhaust after the particulate filter and feeds it in before the turbo compressor. GM's diesels of 2016–18 and FCA's 2.2-litre diesel in the Jeep Wrangler use it. P045D means the drive circuit of valve B is shorted to the supply, or the actuator draws overcurrent with the driver on (comparable to P0490 for valve A). The driver is switched off and EGR B stays inactive. GM lists this code among those that switch off the low-pressure EGR position control, but publishes no thresholds for it; the description follows the comparable valve A checks and CARB, which requires output circuits to be monitored.

Medium severity. Can I keep driving?You can normally drive in moderation, but get it repaired soon: if the valve is stuck open, the engine may idle very poorly.

Symptoms

Check engine light on
Low-pressure EGR switched off, possibly higher NOx
Usually no change in driving

Most likely causes

Control wire shorted to a supply wire
Actuator motor shorted internally (overcurrent)
Moisture or corrosion in the connector
Engine module

What to check, in order

Start with the simplest. You can tick off each step.

Check the connector and any vacuum hoses
Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
Use live data to compare the commanded opening with the actual opening
Clean the valve and passages if they are clogged with carbon
Test the actuator with the scanner
Replace the valve if it still does not follow the command after cleaning

Good to know

Repair difficulty: medium
It can trigger limp mode.
It affects emissions.

What each character of P045D means

P: Powertrain: engine and transmission
0: Generic code: same on every make
4: Emissions
5D: Specific fault in that system

Frequently asked questions

Can I keep driving with code P045D?

You can normally drive in moderation, but get it repaired soon: if the valve is stuck open, the engine may idle very poorly.

What causes code P045D?

The most common causes are: control wire shorted to a supply wire; actuator motor shorted internally (overcurrent); moisture or corrosion in the connector.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.