With 4L60 Transmission

DTC 53 System Voltage High:

System Voltage:

CIRCUIT DESCRIPTION
CKT 439 is the ignition voltage feed for the PCM. CKT 440 is the battery feed for the Powertrain Control Module (PCM).

DTC 53 WILL SET WHEN
^ The ignition is "ON" and the PCM ignition feed voltage is greater than 19.5 volts.
^ All conditions are met for 2 seconds.

ACTION TAKEN (PCM will default to)
^ No Torque Converter Clutch (TCC).
^ Maximum line pressure.
^ Third gear only.

DTC 53 WILL CLEAR WHEN
Fault condition no longer exists, and the ignition switch is cycled "OFF" then "ON."

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This test checks that normal battery voltage is between 9-15 volts.
2. This test checks if the generator is faulty under load conditions. If the voltage is greater than 15 volts, refer to Starting And Charging System.

DIAGNOSTIC AIDS
^ CKT 440 supplies battery voltage to the PCM.
^ Charging the battery with a battery charger and jump-starting an engine may set DTC 53. If DTC(s) set when an accessory is operated, check for faulty connections or excessive current draw.
^ Check for faulty connections at the starter solenoid or fusible link.