Download DTC C1236 Low System Supply Voltage

1999 Oldsmobile Intrigue
DTC C1236 Low System Supply Voltage
Circuit Description
DTC C1236 monitors the voltage level available to the EBTCM controller. If the voltage drops below 11.4 volts, full
performance of the ABS system is not guaranteed. During ABS operation, there are several current requirements that
will cause battery voltage at the EBTCM to drop. As a result, voltage is monitored prior to an ABS event to indicate
good charging system condition. Voltage is also monitored during an ABS event when voltage may drop significantly.
Conditions for Setting the DTC
DTC C1236 can set only if the vehicle's speed is greater than 5 km/h (3 mph).
A malfunction exists if the switched battery voltage is less than 11.4 volts during a non-ABS event or less than 8.4
volts during an ABS event.
Action Taken When the DTC Sets
z
z
z
z
A malfunction DTC stores.
The ABS/ETS disables.
The amber ABS/ETS warning indicators turn on.
The red BRAKE warning indicator turns on if the rear piston in the ABS brake motor pack is not in the home
position.
Conditions for Clearing the DTC
z
z
The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used.
100 drive cycles pass with no DTCs detected.
Diagnostic Aids
Many conditions may cause an intermittent malfunction. Proper use of the scan tool enhanced diagnostic function can
be used in order to measure the frequency of the fault. Thoroughly inspect any circuitry that may be causing the
intermittent complaint for the following conditions:
z
z
z
z
z
z
Backed out terminals
Improper mating
Improperly formed or damaged terminals
Poor terminal-to-wiring connections
Rubbed-through wire insulation
A broken wire inside the insulation
If it is noted that only the ignition voltage drops below acceptable voltage levels after performing a Voltage Load test,
inspect CKT 1339 for high resistance or an open condition.
Step
1
2
3
4
Action
Was the Diagnostic System Check performed?
Value
(s)
Yes
Go to Step 2
No
Go to Diagnostic
System Check ABS
Go to Charging
System Check
Go to Step 3
Go to Step 4
Go to Charging
System Check
Go to Step 5
Go to Step 9
1. Install a scan tool.
2. Turn the ignition switch to the ON position. Do not start
the engine.
3. Select Snapshot on the scan tool.
4. Select Single DTC on the scan tool.
5. Enter C1236 on the scan tool.
6. Drive the vehicle at a speed above 5 km/h (3 mph).
Does DTC C1236 set as a current DTC?
1. Turn the ignition switch to the ON position.
2. Select Special Functions on the scan tool.
3. Use the scan tool in order to perform the Voltage Load test.
10 V
Are the ignition voltage and the battery voltage equal to or
greater than the specified range?
1. Turn the ignition switch to the OFF position.
2. Disconnect the 24-way EBTCM connector C1.
3. Disconnect the 8-way EBTCM connector C2.
4. Disconnect the Electronic Brake Control Relay.
5. Use the J 39200 in order to measure the resistance between
0the Electronic Brake Control Relay harness connector
2 ohms
terminal A2 and the 8-way EBTCM connector C2
terminal C.
Is the resistance within the specified range?
1. Disconnect the negative battery cable.
2. Disconnect the positive battery cable.
3. Use the J 39200 in order to measure the resistance between
5
6
7
8
the positive battery terminal and the Electronic Brake
Control Relay Harness connector terminal C1.
02 ohms
Is the resistance within the specified range?
1. Remove the fuse block ABS/ETS Fuse (10A).
2. Use the J 39200 in order to measure the resistance between
the fuse block terminal C2 (ABS/ETS Fuse [10A]) and the
024-way EBTCM connector C1 terminal A9.
2 ohms
Go to Step 6
Go to Step 10
Is the resistance within the specified range?
1. Inspect the following components:
{ The Electronic Brake Control Relay harness
connector
{ The 24-way EBTCM connector C1
{ The 8-way EBTCM connector C2
{ The positive battery cable connections
{ The negative battery cable connections
2. Inspect the above components for the following conditions:
{ Terminal damage
{ Poor terminal contact
{ Terminal corrosion The above conditions may cause
an open circuit.
Go to Step 7
Go to Step 11
Go to Step 12
Go to Step 8
Go to Step 13
Go to Step 14
--
Go to Diagnostic
System Check ABS
--
--
Go to Diagnostic
System Check ABS
--
--
Go to Diagnostic
System Check ABS
--
Are there signs of terminal damage, poor terminal contact, or
terminal corrosion?
1. Reconnect the 24-way EBTCM connector C1.
2. Reconnect the 8-way EBTCM connector C2.
3. Reconnect the Electronic Brake Control Relay.
4. Reconnect the positive battery cable.
5. Reconnect the negative battery cable.
6. Drive the vehicle at a speed above 5 km/h (3 mph).
--
--
Does DTC C1236 set as a current DTC?
Repair the open or high resistance in CKT 1633.
9
Is the repair complete?
Repair the open or high resistance in CKT 102.
10
Is the repair complete?
Repair the open or high resistance in CKT 1339.
11
12
13
14
Is the repair complete?
Replace all of the terminals or the connectors that exhibit signs of
poor terminal contact, corrosion, or damaged terminals.
Is the repair complete?
Replace the EBTCM. Refer to Electronic Brake Control Relay
Replacement .
Is the repair complete?
Is the malfunction intermittent or is not present at this time?
--
--
--
Go to Diagnostic
System Check ABS
Go to Diagnostic
System Check ABS
Go to Diagnostic
Aids
--
--
--