Buick Riviera 3.8L – Roadmaster 5.7L – Skylark 2.4L – Skylark 3.1L OBD1 Codes

Model	Year	Engine identification	System
Riviera 3.8L	1995-99	VIN position 8 = K/1	GM
Roadmaster S.7L	1996	VIN position 8 = P	GM
Skylark 2.4L	1996-98	VIN position 8 = T	GM
Skylark 3.1 L	1996-98	VIN position 8 = M	GM

General information

Malfunction indicator lamp (MIL) will illuminate or flash if certain faults are recorded.
ECM operates in backup mode if sensors fail , to enable vehicle to be driven to repair shop.

Accessing

Trouble codes can only be displayed by using a Scan Tool connected to the data link connector (DLC).

Erasing

Method 1 • After the faults have been rectified, the manufacturer recommends that trouble codes are erased by using a Scan Tool connected to the data link connector (DLC).

Method 2

NOTE: Disconnecting battery ground lead may cause driveability problems until the engine management system relearns basic values.

Ensure ignition switched OFF for at least 10 seconds.
Disconnect battery ground cable for at least 30 seconds.
Reconnect battery ground cable.
Repeat accessing procedure to ensure no trouble codes remain in ECM fault memory.

NOTE: Disconnecting battery ground lead may also erase memory from electronic units, such as radio.

Trouble code identification

Scan code	Fault location	Probable cause
PO,P2,UO	Refer to OBO-II trouble code tables	–
P1106	Manifold absolute pressure (MAP) sensor circuit intermittent -voltage high	Wiring open circuit/short circuit to positive
P1107	Manifold absolute pressure (MAP) sensor circuit intermittent -voltage low	Wiring open circuit/short circuit to ground
P1111	Intake air temperature (IAT) sensor -circuit intermittent -voltage high	Wiring open circuit/short circuit to positive, ground lead defective
P1112	Intake air temperature (IAT) sensor -circuit intermittent -voltage low	Wiring short circuit to ground
P1114	Engine coolant temperature (ECT) sensor circuit malfunction -voltage low	Wiring short circuit to ground
P1115	Engine coolant temperature (ECT) sensor circuit malfunction -voltage high	Wiring open circuit/short circuit to positive, ground lead defective
P1121	Throttle position (TP) sensor -circuit malfunction -voltage high	Wiring open circuit/short circuit to positive, ground lead defective
P1122	Throttle position (TP) sensor -circuit malfunction -voltage low	Wiring open circuit/short circuit to ground
P1133	Heated oxygen sensor (H02S) 1 -insufficient switching	Wiring open circuit/short circuit to ground, exhaust system leaking, H02S
P1133	Heated oxygen sensor (H02S) 1, bank insufficient switching	Wiring open circuit/short circuit to ground, exhaust system leaking, oxygen sensor heater, oxygen sensor contamination, H02S
P1134	Heated oxygen sensor (H02S) 1 -slow response	Wiring open circuit/short circuit to ground, exhaust system leaking, H02S
P1134	Heated oxygen sensor (H02S) 1, bank 1 slow response	Wiring open circuit/short circuit to ground, exhaust system leaking, oxygen sensor heater, oxygen sensor contamination, H02S
P1153	Heated oxygen sensor (H02S) 1, bank 2-insufficient switching	Wiring open circuit/short circuit to ground, exhaust system leaking, oxygen sensor heater, oxygen sensor contamination, H02S
P1154	Heated oxygen sensor (H02S) 1, bank 2 slow response	Wiring open circuit/short circuit to ground, exhaust system leaking, oxygen sensor contamination,H02S
P1171	Fuel system -lean during acceleration	Fuel filter, fuel lines, fuel pump
P1200	Injector(s) -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, ECM
P1222	Injector control -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, injector(s)
P1257	Boost control problem	Wiring short circuit to ground, hoses blocked/leaking, boost bypass actuator, boost control solenoid, ECM
P1260	Fuel pump speed relay -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, fuel pump relay, fuel pump control module, ECM
P1336	Crankshaft position (CKP) sensor -variation not learned	Learning procedure not performed
P1350	Ignition control module (ICM) -electronic spark timing (EST)!ignition control (IC)!bypass circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, ICM, ECM
P1351	Ignition control module, ignition control (IC) circuit -voltage high	Wiring open circuit, ICM, ECM
P1352	Ignition control (IC) circuit -bypass line voltage high	Wiring open circuit, ICM, ECM
P1361	Ignition control module (ICM) -electronic spark timing (EST)!ignition control (IC)!bypass circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, ICM, ECM
P1362	Ignition control circuit, bypass line -voltage low	Wiring short circuit to ground/short circuit to positive, ICM, ECM
P1371	Direct ignition (01) low resolution circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, distributor, ICM, ECM
P1374	Crankshaft position (CKP)	Wiring open circuit/short circuit to ground/ short circuit to positive, wiring routed near spark plug wires, ignition coils arcing! tracking, ICM, ECM
P1380	Rough road signal -signal error	ASS control module trouble code(s) stored
P1381	Rough road signal -no communication from anti lock brake system (ABS) CAN data bus	Wiring open circuit, ASS system
P1404	Exhaust gas recirculation (EGR) valve -stuck open	Wiring open circuit/short circuit to positive, EGR valve, exhaust system blocked, ECM
P1406	Exhaust gas recirculation (EGR) valve position sensor circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, EGR valve position sensor, EGR valve, ECM
P1415	Secondary air injection (AIR) system -bank 1	Wiring, hoses blocked/leaking, AIR valve
P1416	Secondary air injection (AIR) system -bank 2	Wiring, hoses blocked/leaking, AIR valve
P1441	Evaporative emission (EVAP) system -leak detected	Wiring short circuit to ground, hose connection(s), EVAP system vacuum switch, EVAP canister purge valve, ECM
P1442	Evaporative emission (EVAP) system vacuum switch -circuit malfunction	Wiring open circuit/short circuit to ground, EVAP system vacuum switch, ECM
P1508	Idle air control (lAC) valve -rpm low	Wiring open circuit/short circuit to ground/ short circuit to positive, IAC passages blocked, lAC valve
P1509	Idle air control (lAC) valve -rpm high	Wiring open circuit/short circuit to ground/ short circuit to positive, IAC passages blocked, IAC valve
P1530	AlC refrigerant pressure sensor -circuit malfunction	AlC refrigerant pressure, wiring open circuit/ shortcircuit to ground/short circuit to positive, AlCrefrigerant pressure sensor, ECM
P1539	AlC compressor clutch relay -voltage high	Wiring open circuit/short circuit to ground/ short circuit to positive, AlC compressor clutch relay, ECM
P1545	AlC compressor clutch relay -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, AlC compressor clutch relay, ECM
P1546	AlC compressor clutch relay -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, AlC compressor clutch relay, ECM
P1554	Cruise control status circuit	Wiring short circuit to ground, cruise control module, ECM
P1558	Cruise control servo position sensor -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, hoses leaking, cruise control servo, ECM
P1561	Cruise control vent solenoid	Wiring open circuit/short circuit to ground/ short circuit to positive, cruise control servo, ECM
P1562	Cruise control vacuum solenoid	Wiring open circuit/short circuit to ground/ short circuit to positive, cruise control servo, ECM
P1565	Cruise control servo position sensor -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, TCC solenoid, ECM
P1567	Cruise control switch -circuit malfunction	Wiring open circuit/short circuit to positive, cruise control switch, brake pedal vacuum valve, ECM
P1568	Cruise control servo -servo position sensor high	Hoses blocked, brake pedal vacuum valve, cruise control servo, cruise control cable binding
P1571	Traction control system (TCS), torque requestcircuit	Wiring open circuit/short circuit to ground/ short circuit to positive, ABS control module trouble code(s) stored, ECM
P1573	Data bus -anti lock brake system (ASS)! traction control system (TCS)	Wiring, ABS control module trouble code(s) stored
P1585	Cruise control system -inhibit output circuit	Wiring open circuit/short circuit to ground/ short circuit to positive, supply wire, cruise controlmotor/actuator, ECM
P1599	Cruise control -power management mode	Hoses blocked, brake pedal vacuum valve, cruise control servo, cruise control cable binding
P1601	CAN data bus -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, instrument panel, ECM
P1619	Engine oil life monitor reset switch -circuit malfunction	Wiring short circuit to ground, engine oil life monitor reset switch, ECM
P1621	Engine control module (ECM) -memory performance	ECM
P1623	Engine control module (ECM) -PROM	Insecure PROM, ECM
P1626	Immobilizer control module -fuel enable signal	Incorrect ignition key, wiring open circuit/ short circuit to ground/short circuit to positive, immobilizer control module, ECM
P1629	Immobilizer control module -fuel enable signal	Incorrect ignition key, wiring open circuit/ short circuit to ground/short circuit to positive, immobilizer control module, ECM
P1630	Battery voltage too highllow	Wiring, alternator, ECM
P1635	Sensor supply voltage -circuit A malfunction	Wiring short circuit to positive, ground wiring open circuit, TP sensor, MAP sensor, EGR valve, ECM
P1639	Sensor supply voltage -circuit B malfunction	Wiring short circuit to ground/positive, ground wiring open circuit, AlC refrigerant pressure sensor, ECM
P1640	Engine control module (ECM) quad driver! output driver	Wiring, ECM controlled components, ECM (1)
P1641	Malfunction indicator lamp (MIL) -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, MIL, supply wire, ECM
P1641	AlC compressor clutch relay -circuit malfunction	Wiring open circuit/short circuit to positive, supply wire, AlC compressor relay, ignition main relay, ECM
P1641	Engine coolant blower motor relay 1 -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, supply wire, engine coolant blower motor relay 1, ECM
P1642	Engine coolant blower motor relay 2 -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, supply wire, engine coolant blower motor relay 2, ECM
P1643	Fuel pump control module -circuit malfunction	Wiring open circuit/short circuit to ground/ shortcircuit to positive, fuel pump control module, ECM
P1643	Engine speed output circuit -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, ECM
P1645	Supercharger (SC) control valve solenoid circuitmalfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, SC control valve solenoid, ECM
P1646	Supercharger (SC) control valve solenoid -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, SC control valve solenoid, ECM
P1650	Engine control module, quad driver!output driver	Wiring, ECM controlled components, ECM (1)
P1651	Engine coolant blower motor relay 1 -circuitmalfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, supply wire, engine coolant blower motor relay 1, ECM
P1652	Engine coolant blower motor relay 2 -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, supply wire, engine coolant blower motor relay 2, ECM
P1652	. Vehicle speed output signal -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, instrument panel, ECM
P1653	Traction control system (TCS) -delivered torquecircuit	Wiring open circuit/short circuit to ground/ short circuit to positive, ABS control module trouble code(s) stored, ECM
P1653	Engine oil level warning lamp -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, instrument panel, ECM
P1654	AlC compressor clutch relay -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, supply wire, AlC compressor clutch relay, ECM
P1655	Evaporative emission (EVAP) canister purge valve -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, supply wire, EVAP canister purge valve, ECM
P1661	Malfunction indicator lamp (MIL) -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, MIL lamp bulb, ECM
P1662	Cruise control inhibit circuit -circuit malfunction	Wiring open circuit/short circuit to ground, cruise control motor!actuator, cruise control module,ECM
P1663	Alternator warning lamp -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, supply wire, instrument panel, ECM
P1663	Engine oil level warning lamp -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, engine oil level lamp bulb, ECM
P1665	Evaporative emission (EVAP) canister vent valve-circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, supply wire, EVAP canister vent valve, ECM
P1667	Fuel pump control module -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, supply wire, fuel pump control module, ECM, fuel pump relay
P1670	Engine control module (ECM) quad driver! output driver	Wiring, ECM controlled components, ECM EJ
P1671	Malfunction indicator lamp (MIL) -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, supply wire, ECM
P1672	Engine oil level warning lamp -circuit malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, supply wire, ECM
P1673	Engine coolant ‘hot’ warning lamp -circuit malfunction	Wiring open circuit/short circuit to ground, cooling system, ECM
P1675	Evaporative emission (EVAP) canister vent valve -circuit malfunction	Wiring open circuit/short circuit to ground/ short to positive, EVAP canister vent valve, ECM
P1676	Evaporative emission (EVAP) canister purge valve -circuit malfunction	Wiring open circuit/short circuit to ground/ . short circuit to positive, supply wire, EVAP canister purge valve, ECM
P1689	Traction control system (TCS) -delivered torque output circuit	Wiring open circuit/short circuit to ground/ short circuit to positive, supply wire, ABS trouble codes stored, ECM
P1860	Torque converter clutch (TCC) solenoid circuit malfunction	Wiring open circuit/short circuit to ground, TCC solenoid, ECM
U1016	Instrument panel, CAN data bus -communication malfunction	Wiring open circuit/short circuit to ground/ short circuit to positive, instrument panel, ECM

Riviera 3.8L 1998 VIN 1
Riviera 3.8L 1999 VIN 1
Roadmaster 5.7L 1996 VIN P
Skylark 3.1 L 1998 VIN M
Except Roadmaster 5.7L 1996 VIN P
Except Riviera 3.8L 1998 VIN 1, Skylark 3.1L 1998 VIN M & Roadmaster 5.7L 1996 VIN P
Except Riviera 3.8L 1999 VIN 1 & Roadmaster 5.7L 1996 VIN P
Depending on model , year and equipment level , the following components may be connected to this circuit.

Use of the vehicle wiring diagram is recommended to confirm which components are fitted.
A/C compressor clutch relay
A/C condenser blower motor relay
Engine coolant blower motor relay
Engine coolant ‘hot’ warning lamp
Evaporative emission (EVAP) canister purge valve
Exhaust gas recirculation (EGR) solenoid
Malfunction indicator lamp (MIL)
Torque converter clutch (TCC) solenoid
Transmission shift solenoids (SS)
Transmission shift warning lamp (MT)