P216B: Fuel Injector Group E Supply Voltage Circuit Low

What does P216B mean?

P216B reports the feed of injector group E pulled toward ground. In GM petrol direct injection, group E means the injector of cylinder 5, so the code appears on V6 and V8 engines. GM's 2016 3.6 LGX V6 and 2018 6.2 LT4 V8 tables treat it as the injector 5 high-side line being grounded: while the driver is switched on, 25 A or more flows through it. With at least 11 V, 10 failures out of 20 samples at 100 ms set the code, type A, so the MIL lights on the first trip. GM's preliminary information PI0631H for 2012 and 2013 Impala found the engine harness chafing against a transmission edge, which can ground a single circuit such as this one. The injector is shut off and cylinder 5 drops out. P216A is the general fault, P216C the short to voltage.

The code tells you which monitor failed, not which part is broken. Test before replacing parts.

Symptoms

• Check engine lamp on immediately
• Cylinder 5 misfire, noticeable shaking

Common causes

• High High-side wire of injector 5 chafed through to ground, for example on the transmission
• Medium Cylinder 5 injector shorted to its housing
• Low Engine control module output stage faulty

Likelihood is a general estimate across vehicles; your make and model may differ.