I042

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

These codes will set if the engine RPM is greater than 800, the IPC can communicate with the PCM (code I034 not set), and the ignition 1 voltage at the IPC is outside its normal range for 2 seconds. If voltage is less than 10.6 volts code I041 will set and the DIC will display "BATTERY VOLTS LOW". If voltage is more than 16 volts code I042 will set and the DIC will display "BATTERY VOLTS HIGH". While either of these codes are current, all other IPC codes (except I052) will not set. If voltage falls below approximately 9.0 volts the IPC will temporarily stop functioning.

TEST DESCRIPTION

Test numbers refer to circled numbers on the diagnostic chart.

1. If the PCM and IPC are not "seeing" the same battery voltage, then the IPC voltage sense and ground are suspect.

2. This checks the battery and charging systems ability to maintain proper voltage under a high load condition.

3. This checks for an over-voltage condition at high RPM and low electrical load.

NOTES ON INTERMITTENTS

If an intermittent code I041 or I042 is being set, observe IPC I041/I042 snapshot data value for ID50. This will show the voltage at the time the code was set. Snapshot information for parameters 1D60 (vehicle speed), II94 (parklights ON/OFF), and II10 (generator feedback) may also be useful in determining vehicle conditions when the code is being set.

Verify good connections at IPC A5, C13, and C16. Check to ensure good tight grounds. Refer to "BATTERY AND CHARGING DIAGNOSIS" IN STARTING AND CHARGING. Starting and Charging