Send to Ford
or
go through the subroutine to determine the fault and fix what the problem is
or
change the Airbag Diagnostic Monitor yourself. Good luck.
From 1996 Ford CD Manual
DTC 52: BACK-UP POWER SUPPLY -- VOLTAGE BOOST FAULT
Normal Operation
A back-up power supply is contained within the air bag diagnostic monitor that consists of a capacitor and a voltage boost circuit. The voltage boost circuit charges the capacitor to approximately 24 volts (�± 1 volt) when the ignition switch is turned to RUN. The back-up power supply is connected through a diode to diagnostic monitor Pin C1-15, Circuit 29 (O). The resistance of Circuit 29 (O) to ground is infinite since it is an open circuit. This open circuit allows the capacitor to maintain its higher voltage because there is no discharge path for the capacitor. The air bag diagnostic monitor measures the voltage on the back-up power supply capacitor. If the voltage on the capacitor does not reach and maintain a minimum of 23 volts after approximately 45 seconds, the air bag diagnostic monitor will flash Code 52 to indicate low voltage in the back-up power supply voltage boost circuit.
Possible Causes
Low back-up power supply voltage can be caused by:
(1) Resistance on Circuit 29 (O) or Circuit 7 (Y/BK) to ground. Resistance to ground on Circuit 29 (O) or Circuit 7 (Y/BK) will cause the back-up power supply capacitor to discharge and the boost circuit will not be able to boost the voltage.
(2) Boost circuit failure within the air bag diagnostic monitor. If the voltage boost circuit in the air bag diagnostic monitor is damaged, it will not be able to raise the back-up power supply voltage on the capacitor.
Electrical Schematic--Diagnostic Trouble Code 52
�² 52-1: CHECK FOR DIAGNOSTIC TROUBLE CODE
�² 52-2: MEASURE VOLTAGE AT PIN C1-15
�² 52-3: MEASURE RESISTANCE BETWEEN PINS C1-15 AND C1-3
�² 52-4: MEASURE RESISTANCE AT THE CONNECTOR
�² 52-5: CHECK FOR SHORT IN RH KICK PANEL REAR SAFING SENSOR
DTC 52: BACK-UP POWER SUPPLY -- VOLTAGE BOOST FAULT
52-2 MEASURE VOLTAGE AT PIN C1-15
l Deactivate system.
l Turn ignition switch from OFF to RUN.
l Wait 45 seconds.
l Measure voltage between Pin C1-15, Circuit 29 (O) and Pin C1-3, Circuit 91 (BK/R), ground.
l Is voltage measured 24 �± 1 volt?
Yes
REPLACE air bag diagnostic monitor. RECONNECT system. VERIFY system. REACTIVATE system.
No
GO to �«52-3�».
52-3 MEASURE RESISTANCE BETWEEN PINS C1-15 AND C1-3
l Turn ignition switch to OFF.
l Disconnect air bag diagnostic monitor.
l With Rotunda 73 Digital Multimeter 105-R0051 or equivalent, measure resistance of Pin C1-15, Circuit 29 (O) to Pin C1-3, Circuit 91 (BK/R), ground.
l Is resistance measured greater than 100K ohms?
Yes
REPLACE air bag diagnostic monitor. RECONNECT system. VERIFY system. REACTIVATE system.
No
GO to �«52-4�».
52-4 MEASURE RESISTANCE AT THE CONNECTOR
l Disconnect RH kick panel rear safing sensor.
l Measure resistance between Pin C1-15, Circuit 29 (O) and Pin C1-3, Circuit 91 (BK/R), ground at the air bag diagnostic monitor harness connector.
l Is resistance measured greater than 100K ohms?
Yes
GO to �«52-5�».
No
LOCATE and SERVICE short to ground in Circuit 29 (O). RECONNECT system. VERIFY system. REACTIVATE system.
52-5 CHECK FOR SHORT IN RH KICK PANEL REAR SAFING SENSOR
l Measure resistance of (O) wire in RH kick panel safing rear air bag sensor connector to sheet metal ground.
l Is resistance measured greater than 100K ohms?
Yes
LOCATE and SERVICE short to ground in Circuit 7 (Y/BK). RECONNECT system. VERIFY system. REACTIVATE system.
No
REPLACE RH kick panel safing sensor and bracket. RECONNECT system. VERIFY system. REACTIVATE system.
Last edited by Tony2005; 02/04/06 10:25 PM.
