Without Scan Tool

Description



The test bulb will only illuminate under the conditions listed below when a malfunction exists. If the malfunction is corrected, the light will go out and the code will be reset, except for trouble code 12. If the test bulb goes on intermittently, but no code is displayed when the test lead is grounded, refer to this symptom when diagnosing "Driver Complaints".

When test bulb is not on with engine operating, but a fault code can be obtained, the problem must be checked to determine if the fault is intermittent or is due to engine operating conditions.

For all codes except 13, 44 and 45, the test bulb should be on with engine speed below 800 rpm after five minutes of operation.

If codes other than 13, 44 and 45 can be obtained with the test bulb off, the diagnostic charts cannot be used since the system is operating normally. All that can be done is inspect the circuit indicated by the trouble code. These circuits should be checked for poor connections, frayed wires, etc. The "System Operational Check," Chart 1, should be performed.

Trouble codes 13, 44 and 45 require that the engine be operated at part throttle under load for an extended period of time before the test bulb goes on or a code is flashed.

Trouble code 15, requires that the engine be operated 5 minutes before the test but goes on or code is flashed. The applicable diagnosis should be used if these codes can be obtained at idle even though the test bulb is not on at idle.