P2AF7 Starter Relay D Control Circuit/Open

P2AF7 is the open-circuit or general fault on the control line of a fourth starter relay, relay D. Four separately monitored starter relays only make sense where there is more than one cranking path, for example a pinion relay, a second starter or a battery isolation stage on a stop-start engine. No manufacturer documents P2AF7 publicly, and the Stellantis bulletins that use relay C do not name a relay D. CARB requires engine computers to monitor output components for lost continuity. As a comparison, GM considers its relay A and B outputs open once the circuit looks like 200 kΩ or more toward ground, after 40 failures in 50 samples. Typical causes are a broken wire, a corroded plug, an open coil or a blown supply fuse. P2AF8 and P2AF9 separate the grounded and the live control wire.

Likely causes

Symptoms

• Auto-stop not available
• Intermittent no-crank
• Stored code, lamp depending on manufacturer

Repair estimate

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

Related codes

References: law.cornell.edu, gsi.ext.gm.com.