Captiva |
||||||||
|
|
• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provide an overview of each diagnostic category. |
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
Fuel Economy Mode Switch 5 V Reference | P159F | P159F, P15A1 | P159F | P15A0 | P15A1 |
Fuel Economy Mode Switch Signal | P159F | P159F | P159F | P15A0 | P15A1 |
Fuel Economy Mode Switch Ground | - | P15A0, P15A1 | P15A0 | - | P15A1 |
The ECM supplies 5 V reference voltage, through the 5 V reference voltage circuit, to the fuel economy mode switch. The 5 V reference voltage causes current to flow through a series of resistors in the switch to the switch ground circuit. The ECM monitors the reference voltage through a discrete fuel economy mode switch signal circuit. When the switch button is momentarily pressed, the switch contacts allow the 5 V reference voltage to by-pass one of the resistors. The ECM detects the resulting voltage drop as a fuel economy mode request and sends a GMLAN message to the transmission control module (TCM) indicating the request. When the TCM receives the request, throttle progressions and transmission shift points are modified to optimize fuel efficiency. The instrument panel cluster (IPC) also receives the fuel economy mode request message from the ECM and illuminates the fuel economy mode indicator lamp. The fuel economy mode switch must be pressed for between 0.094-1.5 s to activate the fuel economy mode. Voltage on the signal wire is normally between 1.45-3.45 V with the switch depressed. When the switch is released, voltage on the signal wire is normally between 3.65-4.45 V.
• | Ignition key must be turned to ON. |
• | DTCs P159F and P15A0 run continuously when the above condition is met. |
The ECM detects that the voltage on the fuel economy mode switch signal wire is either too low or too high out of range.
DTCs P159F and P15A0 are Type B DTCs
DTCs P159F and P15A0 are Type B DTCs
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
Note: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
⇒ | If greater than the specified range, test the ground circuit for a open/high resistance and repair as necessary. If the circuit tests normal, replace the K20 ECM. |
⇒ | If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM. |
⇒ | If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM. |
⇒ | If the parameter does not display the specified value, test the signal circuit for a short-circuit to voltage. If the circuit tests normal, replace the K20 ECM. |
⇒ | If the DMM does not measure between 266-294 Ω, replace the S112 fuel economy mode switch. |
⇒ | If the DMM does not measure between 1,414-1,562 Ω, replace the S112 fuel economy mode switch. |
⇒ | If the DMM does not measure between 486-538 Ω, replace the S112 fuel economy mode switch. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Refer to Transmission Control Replacement for fuel economy indicator switch replacement. |
• | Control Module References for ECM replacement, setup and programming |
© Copyright Chevrolet. All rights reserved |