Probable Causes:
- A/C Switch or Switch Circuit
- A/C Amplifier
- Accelerator Pedal or Cable
- ECM
- Neutral/Start Switch or Switch Circuit
- Throttle Position Sensor or Sensor Circuit
To check throttle position sensor or circuit, see CODE 41/TEST NO. 6 - TPS SIGNAL procedures in this article. To check A/C switch signal, use the following table.
CODE 51 - SWITCH SIGNAL TROUBLE
| Terminal | Trouble | Condition | STD Voltage |
|---|---|---|---|
| A/C -E1 | No Voltage | Air conditioning ON | 9-14V |