Suzuki XL7 2007 Service Manual page 201

P0138, P0140, P0158, and P0160
• The HO2S heater is at operating temperature.
• The engine is operating for greater than 1 second.
• The ignition voltage is more than 10.5 volts.
• The calculated exhaust temperature is between 250-
800°C (482-1,472°F) for more than 90 seconds.
• DTCs P0138 and P0158 run continuously once the
above conditions are met for greater than 5 seconds.
• DTCs P0140 and P0160 run continuously once the
above conditions are met for greater than 60 seconds.
Conditions for Setting the DTC
P0137 or P0157
The ECM detects that a secondary HO2S signal voltage
is less than 60 mV for greater than 4 seconds of for a
cumulative of 50 seconds.
P0138 or P0158
The ECM detects that the HO2S signal voltage is more
than 1,080 mV for greater than 4 seconds or for a
cumulative of 50 seconds.
P0140 or P0160
• The ECM detects that the HO2S voltage is between
401-519 mV.
• The ECM detects that the measured internal
resistance of the HO2S is greater than 40,000 ohms,
when the calculated exhaust temperature is greater
than 600°C (1,112°F).
• Either condition exists for greater than 4 seconds or
for a cumulative of 50 seconds.
Action Taken when the DTC Sets
DTCs P0137, P0138, P0140, P0157, P0158, and P0160
are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P0137, P0138, P0140, P0157, P0158, and P0160
are Type B DTCs.
Reference Information
Schematic Reference
"Engine Controls Schematics"
Connector End View Reference
• "Engine Control Module Connector End Views"
• "Engine Controls Connector End Views"
Electrical Information Reference
• "Circuit Testing: "
• "Connector Repairs: "
• "Testing for Intermittent Conditions and Poor
Connections: "
• "Wiring Repairs: "
DTC Type Reference
"Powertrain Diagnostic Trouble Code (DTC) Type
Definitions"
Engine General Information and Diagnosis:
Scan Tool Reference
• "Scan Tool Data List - Engine Controls - 3.6L (LY7)"
• "Scan Tool Data Definitions - Engine Controls - 3.6L
(LY7)"
• "Scan Tool Output Controls - Engine Controls - 3.6L
(LY7)"
Circuit/System Verification
1. With the engine running, observe the heated oxygen
sensor (HO2S) voltage parameter. The reading
should fluctuate above and below the range of 350-
550 mV.
2. If the vehicle passes the Circuit/System Verification
Test, then operate the vehicle within the conditions
for running the DTC. You may also operate the
vehicle within the conditions that are captured in the
Freeze Frame/Failure Records Data List.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at
the appropriate HO2S.
2. Ignition ON, verify that the applicable HO2S voltage
parameter is between 350-500 mV.
➢ If less than the specified value, test the signal
circuit for a short to ground. If the circuit/
connections test normal, replace the ECM.
➢ If greater than the specified value, test the signal
circuit for a short to voltage. If the circuit/
connections test normal, replace the ECM.
3. Install a 3A fused jumper wire between the signal
circuit terminal B and ground. Verify the HO2S
voltage parameter is less than 60 mV.
➢ If greater than the specified value, test the signal
circuit for an open/high resistance. If the circuit/
connections test normal, replace the ECM.
4. Connect a 3A fused jumper wire between the signal
circuit terminal B and the low reference circuit
terminal A. Verify the HO2S voltage parameter is
less than 60 mV.
➢ If greater than the specified value, test the low
reference circuit for an open/high resistance or for a
short to voltage. If the circuit/connections test
normal, replace the ECM.
5. Verify that the following conditions do not exist:
– Lean, rich, or leaking fuel injectors—Refer to "Fuel
Injector Balance Test with Special Tool: " or "Fuel
Injector Balance Test with Tech 2: ".
– A fuel pressure that is too low or too high—Refer
to"Fuel System Diagnosis: ".
– Fuel that is contaminated—Refer to "Alcohol/
Contaminants-in-Fuel Diagnosis (w/o Special
Tool): " "Alcohol/Contaminants-in-Fuel Diagnosis
(w/ Special Tool): ".
– Evidence of water intrusion into the electrical
connector of the HO2S
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