PowertrainP0688

Serious

Severity: Serious - have it checked soon

ECM/PCM Power Relay Sense Circuit/Open

33 brands affected · Generic SAE J2012 description.

Key terms: Control module: a small computer that runs one part of the car · SAE J2012: the standard generic code list · Powertrain: engine, transmission and emissions

1What it means in plain English

The engine computer or one of its output circuits has a fault.

2Common causes

Engine control module fault
Power or ground connection problem
Low battery or charging voltage
Wiring short or open circuit
Software or memory fault

3Can I drive?

Serious · drive with care

If the engine runs normally, drive carefully to a workshop for diagnosis. If it runs badly, stalls, or will not restart, have the car towed.

This page gives general information. It is not professional advice. For a definite diagnosis and a repair quote, ask a qualified mechanic to inspect the car.

4Brand data 33

Brand	Code	Description	System
Ashok Leyland CV	P0688	ECM/PCM Power Relay Sense Circuit/Open SAE	Powertrain
BAIC Motor	P0688	ECM/PCM Power Relay Sense Circuit/Open Brand	Powertrain
BYD	P0688	ECM/PCM Power Relay Sense Circuit/Open Brand	Powertrain
Chery	P0688	ECU power supply without voltage Brand	Powertrain
Chrysler	P0688	ECM/PCM Power Relay Sense Circuit/Open SAE	Powertrain
Daewoo	P0688	ECM/PCM Power Relay Sense Circuit/Open Brand	Powertrain
Daihatsu	P0688	IGCT voltage monitoring circuit error Brand	Powertrain
DFFS	P0688	ECM/PCM Power Relay Sense Circuit/Open Brand	Powertrain
DFFX	P0688	ECM/PCM Power Relay Sense Circuit/Open Brand	Powertrain
DFXK	P0688	Main Relay Output Voltage Implausible Brand	Powertrain
EOBD	P0688	Sirkuit/terbuka relay daya ECM/PCM Brand	Powertrain
Geely	P0688	Main Relay Output Voltage Implausible Brand	Powertrain
GM	P0688	ECM/PCM Power Relay Sense Circuit/Open Brand	Powertrain
Great Wall	P0688	Main relay output voltage implausible Brand	Powertrain
Hafei	P0688	ECM/PCM Power Relay Sense Circuit/Open Brand	Powertrain
Holden	P0688	Engine Controls Ignition Relay Feedback Circuit Brand	Powertrain
Hyundai	P0688	ECM/PCM Power Relay Sense Circuit/Open SAE	Powertrain
Isuzu	P0688	ECM/PCM Power Relay Sense Circuit/Open SAE	Powertrain
Land Rover	P0688	ECM/PCM Power Relay Sense Circuit/Open Brand	Powertrain
Maserati	P0688	ECM/PCM Power Relay Sense Circuit/Open SAE	Powertrain
Mitsubishi	P0688	ECU PWR. relay sense circuit open Brand	Powertrain
Opel	P0688	ECM/PCM Power Relay Sense Circuit/Open Brand	Powertrain
Perodua	P0688	IGCT voltage monitoring circuit error Brand	Powertrain
Peugeot	P0688	ECM/PCM Power Relay Sense Circuit/Open SAE	Powertrain
Porsche	P0688	Hauptrelais Brand	Powertrain
Proton	P0688	ECU PWR. relay sense circuit open Brand	Powertrain
Saab	P0688	ECM/PCM Power Relay Sense Circuit/Open Brand	Powertrain
MG (SAIC)	P0688	ECM/PCM Power Relay Sense Circuit/Open Brand	Powertrain
Suzuki	P0688	ECM/PCM Power Relay Sense Circuit/Open SAE	Powertrain
SWM Motor	P0688	Main relay output voltage signal failure Brand	Powertrain
Tata	P0688	ECM/PCM Power Relay Sense Circuit /Open Brand	Powertrain
Toyota	P0688	ECM/PCM power relay sense circuit/open Brand	Powertrain
Volkswagen	P0688	ECM Power Relay Load Circuit: (J271): Open Circuit Brand	Powertrain

Legend: SAE is the generic J2012 description; Brand is text taken from that manufacturer’s data. Manufacturer rows keep the wording and language of the source data, and non-English text is tagged so screen readers pronounce it correctly.

5Extended variant codes 1

These 7-character codes are manufacturer-specific variants of P0688 and may be reported by some scan tools.

Brand	Code	Description	System
Mercedes-Benz	P068800	Der Eingang 'Klemme 87 (Verbrennungsmotor)' hat einen elektrischen Fehler oder Unterbrechung. Brand	Powertrain

6Related codes

Browse Pxxx codes or P068xx codes.