P05C7

Code

Generic P — Powertrain

Economy Mode Switch Circuit/Open

Brand: Generic

Type: P — Powertrain

Views: UK: 26 EN: 62 RU: 37

AI status

Completed

ready

Completed 100%

Page language: EN

ECO/Economy mode indicator will not illuminate or economy mode cannot be selected
DTC P05C7 stored in ECU and possibly MIL illumination (manufacturer dependent)
Vehicle may remain in normal or default shift/engine mode
Intermittent behavior if circuit is failing intermittently

Retrieve freeze frame/related codes and note operating conditions when code set
Visual inspection of switch, connectors and wiring for damage, corrosion, or loose terminals
Inspect relevant fuses and power/ground feeds for the switch circuit
Backprobe the switch connector with ignition ON and operate the switch while monitoring voltage
Check continuity between the switch terminal and the control module input pin with harness disconnected
Wiggle-test harness to reproduce intermittent opens

Logic signal expected to switch between near-battery voltage (approx. battery voltage) and near 0 V depending on switch design
Open-circuit condition: very high resistance / infinite continuity reading between switch terminal and module input
Closed switch continuity: low resistance (typically a few ohms); exact resistance varies by design
No-response: no change in voltage when the switch is operated

Read and record all codes and freeze-frame data. Note whether other related body or BCM codes are present.
Perform a visual inspection of the switch, its mounting, connector and the wiring harness for damage, corrosion or loose pins.
Verify fuses and power/ground feeding the switch. Repair any blown fuses or poor grounds before further testing.
With ignition ON (engine off), backprobe the switch connector and observe the signal while operating the switch. Confirm the signal changes between high and low states.
If no change, disconnect the harness at the switch and measure continuity between the switch circuit pin at the switch connector and the corresponding pin at the control module. Repair any open wiring.
If wiring continuity is good, bench-test or substitute a known-good switch (where available) or measure the switch resistance to confirm operation. Replace switch if faulty.
If switch and wiring check good but no input at ECU, check for correct power/ground at the module input and inspect connector pins. Repair as needed.
If wiring, power and the switch are all confirmed good and the input remains unresponsive, suspect control module input driver fault; consult manufacturer guidance before replacing module.
After repair, clear codes and verify the fault does not return with functional test and road test under relevant conditions.

Wiring harness damage between switch and control module (chafing, pinched, broken)
Connector corrosion or loose terminal at the switch or module
Failed economy mode switch
Blown fuse or supply/ground fault