Fault codeP0886

TCM Power Relay Control Circuit Low

What this code means

TCM Power Relay Control Circuit Low.

P0886 is a generic code: it means the same thing on every make. P0886 belongs to family P08xx — Transmission (continued). Its page explains how to read a code and groups all its codes by part.

Type of fault

The control unit reads a voltage on this circuit below its expected range. Usual causes: a wire shorted to ground or broken, a corroded or loose connector, or the component itself. Check the wiring and connector before replacing the part — that is where many of these faults turn out to be.

Gearbox control unit (TCM)

The gearbox control unit drives the solenoids and reads the gearbox sensors. It communicates with the engine control unit over the vehicle network and is fed by its own relay and fuse.

What you notice

The gearbox goes into limp mode, sometimes several warnings at once, shifts that do not happen.

How to check it

Check its fuses and relay, then the battery voltage and the grounds: a weak supply causes many of these faults. Then the connectors of the unit, which on some cars sits on the gearbox itself and suffers from heat and leaks.

What to do

Have it checked this week. The car remains usable, but the fault will not clear itself and will fail the roadworthiness test.

How to read this code

• PPowertrain
• 0standardised code
• 8Transmission (continued)
• 86P0886

Other codes for the same part

• P0880TCM Power Input Signal
• P0881TCM Power Input Signal Range/Performance
• P0882TCM Power Input Signal Low
• P0883TCM Power Input Signal High
• P0884TCM Power Input Signal Intermittent
• P0885TCM Power Relay Control Circuit /Open
• P0887TCM Power Relay Control Circuit High
• P0888TCM Power Relay Sense Circuit
• P0889TCM Power Relay Sense Circuit Range/Performance
• P0890TCM Power Relay Sense Circuit Low
• P0891TCM Power Relay Sense Circuit High
• P0892TCM Power Relay Sense Circuit Intermittent