P0121

DTC P0121
Throttle pot signal inconsistent with MAF, IACV, air temp and engine rpm (Driving Cycle B)

Possible causes by suggested order of priority:
- Connectors C636, C175.
- Circuit integrity C636/36 (RB) - C175/3 (RB).
- Circuit integrity C635/4 (R) - C175/1 (R).
- Circuit integrity C636/15 (YLG)- C175/2 (YLG).
- Sensor supply from ECM.
- Throttle position sensor.
- ECM.

Connectors C636, C175.
- Check for connector not correctly latched, backed out pins, damaged pins, corroded pins

Circuit integrity C636/36 (RB) - C175/3 (RB).
- Check for open circuit, short circuit to ground, supply or other circuit, damaged or unlatched connector, intermediate connectors or headers

Circuit integrity C635/4 (R) - C175/1 (R).
- Check for open circuit, short circuit to ground, supply or other circuit, damaged or unlatched connector, intermediate connectors or headers

Circuit integrity C636/15 (YLG)- C175/2 (YLG).
- Check for open circuit, short circuit to ground, supply or other circuit, damaged or unlatched connector, intermediate connectors or headers

Sensor supply from ECM.
- Supply to throttle position sensor from ECM C635/4 (R).
- Ensure ignition is ON (position 2).
PASS VALUES: Minimum 2.0 Volts.

Throttle position sensor.
- Throttle position sensor resistance.
- Slowly depress the throttle pedal.
- The reading should change smoothly from below 170 ohms to above 900 ohms.

ECM.
- No detail available for this fault