P2A89: Alternative Fuel Pump C Compression Stroke Valve Control Circuit Low

P2A89 is set when the drive circuit of pump C's compression stroke valve reads low for the commanded state. Most often the control wire has found a path to ground, so the solenoid may stay on, or the coil has shorted turns and pushes the output stage into current limiting. A valve stuck in fill keeps pressurised oil behind element C; that element stops cycling, and the others have to carry its share. Expect reduced fuel delivery at high load rather than an immediate stall, at least on pumps with several elements like Caterpillar's design. No manufacturer publishes P2A89. Unplug valve C and check whether the short to ground remains in the harness; if it disappears, the coil is the likely culprit.

High severity. Can I keep driving?If you smell gas, do not keep driving or start the engine: move away and call for assistance. With no smell, drive moderately to an authorized shop.

Symptoms

Warning lamp on
Reduced power at high load

Most likely causes

Control wire of valve C shorted to ground
Shorted turns in the coil of valve C

What to check, in order

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

If you smell gas, shut off the supply, ventilate and do not start the engine
With the connector unplugged, check whether the signal wire is making contact with ground.
Read the codes with a compatible scanner
Check the connectors and wiring of the component indicated
Leave any work on the gas circuit to an authorized shop

Good to know

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

What each character of P2A89 means

P: Powertrain: engine and transmission
2: Generic code: same on every make
A: Hybrid or air and fuel
89: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2A89?

If you smell gas, do not keep driving or start the engine: move away and call for assistance. With no smell, drive moderately to an authorized shop.

What causes code P2A89?

The most common causes are: control wire of valve C shorted to ground; shorted turns in the coil of valve C.

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.