TEST TC-16A - LEFT OR RIGHT IDLE ADAPTIVE MEM AT LEAN OR RICH LIMIT (DTC 52 or 51)

WARNING: This page is about a different car, the 1995 Dodge Ram Wagon, 1995 Dodge Ram Van, 1995 Dodge Pickup, 1995 Dodge Dakota, and 1995 Dodge Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

These trouble codes may set for several reasons not related to Powertrain Control Module (PCM) electronics. Idle adaptive memory is designed to aid in air/fuel control. Its function is to adapt air/fuel mixture to correct for fuel pressure differences and mechanical changes such as engine wear and mechanical malfunctions.

These trouble codes affect following systems:

Dual O2S System

PCM reaches its operating limit when one O2S indicates a continuous lean or rich exhaust gas mixture. O2S responsible is disabled and other O2S takes over. If both sensors are indicating excessive lean or rich readings, fuel control system goes into open loop mode.

Single O2S System

Fuel control system goes into open loop when O2S indicates a continuous lean or rich exhaust gas mixture.

Following definitions apply to RIGHT (or LEFT) IDLE ADAPTIVE MEM AT LEAN (or RICH) message:

RIGHT (Or LEFT) IDLE ADAPTIVE MEM AT LEAN PCM tries to adapt air/fuel mixture richer.
RIGHT (Or LEFT) IDLE ADAPTIVE MEM AT RICH PCM tries to adapt air/fuel mixture leaner. Possible causes of RIGHT (or LEFT) IDLE ADAPTIVE MEM AT LEAN (or RICH) message are:
Ignition coil and secondary wires.
Catalyst.
EGR valve assembly.
MAP sensor.
Fuel pump and filter.
Fuel injectors.
O2S.
Fuel pressure regulator.
Exhaust system.
Wiring harness/connectors.
Excessive engine wear.
Engine mechanical malfunctions.

Perform following tests in order given until problem is found:

Fuel pressure, perform TEST NTC-3A.
Ignition system, perform TEST NTC-2A.
Coolant Temperature Sensor (CTS), perform TEST NTC-4A.
MAP sensor, perform TEST NTC-6A.
EGR system, perform TEST NTC-13A.
O2S switching, perform TEST NTC-7A.
Engine mechanical, perform TEST NTC-16A.